Where do I start?
First of all, I do both 2D and 3D CAD design work.
I am a relative newcomer to TC Pro but have used AutoCAD, DraftSight and Inventor for a long, long time.
I find that neither Inventor or TC Pro are particularly friendly for pure 2D work, though I would have to give a slight edge to TC Pro in that regard.
For 2D at work I use AutoCAD, and at home I use DraftSight (the free version).
For all intents the user interface is very similar between the two and they both work on .dwg files without any differences that matter (but I am not using every possible subtle feature of either program).
So unless you want to invest in AutoCAD for 2D, my advice would be to go with DraftSight.
For 3D, I have literally thousands of hours experience with Inventor so I can do things with it without really having to think (much) about how I do it.
I used to love Mechanical Desktop which was basically an extension of AutoCAD AME-3D.
In fact it more or less "was" AutoCAD launched with a different set of command line arguments.
I loved it because you could just switch seamlessly between 2D and 3D designs almost at will.
But AutoDesk killed it off a number of years ago in favor of Inventor for reasons of their own that were never adequately explained IMHO.
Take something really basic like creating a block and putting a hole in one of its faces.
Simple concept right?
Start with a sketch plane.
Click on the "I" icon at the ULH corner, click new, then click standard.ipt and create.
Depending upon the particular version you have and how it is configured you will either get a sketch plane immediately or will need to right click and select one.
Draw a rectangle (or square or whatever shape you want).
Right click and you can access dimensioning.
Click on a feature and accept the dimension as it is or type in what you want it to be.
"Finish" the sketch mode.
Type the letter E to launch the extrusion dialog box.
Type in the distance you want it extruded, go to the second tab if you want to change the "angle" (taper) and when happy with it all, click accept and there it is.
To put a hole in a face, hover over the face, right click and click new sketch.
Draw a circle (or square, or whatever), exit the sketch mode, and enter E again.
Select the region you just drew and decide what option you want (add, subtract, mid-plane, etc and how far) and accept.
And it is that easy.
Change your mind?
Right click on the feature you want to change in the browser bar, edit or delete it and the model updates.
TC Pro, as I said, is relatively new to me (<6 months) and is used exclusively at home so I just don't have the hours with it yet.
For that reason I don't have that seamless comfort level yet but I suspect that as I get more accustomed to it I will eventually like it better..
I can tell you that the TC Pro interface seems at present to be more cluttered than Inventor's, not that Inventor's is not confusing at times.
It also is not nearly as intuitive in general (with the caveat of my Inventor background).
There is for example a toggle between 2D and 3D modes.
Darned if I can remember where it is so I have to search for it every time I want it.
Sketching is similar in nature, but you can use the quick pull option to extrude a feature even while in the sketch mode (nice).
And, you can enter dimensions manually of course, but you need to tab to the data entry fields at the bottom of the screen rather than just right clicking.
And it festoons your display with menu bars (the use of dual monitors is advisable).
To be fair though, Inventor is only marginally better in this regard.
Escape does not exit a command, enter or space bar do. This takes getting used to.
One nice thing though it that you can easily customize the right mouse click to pop up just about any commands you want. Dozens of them if that suits you.
The real differences comes in when you want to do something that is dead simple in Inventor (like putting that hole in a surface).
You have to create the new feature on a face or plane or whatever, extrude it and perform a separate boolean operation on it (under the top menu "modify" selection).
This is is not as seamless and intuitive as Inventor and definitely takes longer and a lot more mouse clicks to accomplish.
It is also considerably more difficult, though not impossible, to back-edit features and dimensions if you need to do so after the fact.
Worse, you can't just go into a convenient menu of drawn features (yes, I know there is one, but it is not convenient) and delete a single item up the chain as easily (this is super simple in Inventor).
They both are a bit "tweaky" (for lack of a better term) and you will fight them and fight them and curse them until they have you just where they want you to be.
The learning curve for Inventor was somewhat difficult for me because I had close to 20 years of AutoCAD, AME3D and Mechanical Desktop prior experience and Inventor is different in the way it handles things.
But I am OK with it now.
For 2D, DraftSight is a virtually seamless and painless transition for me from AutoCAD.
Not so for TC Pro from Inventor.
It uses a really different set of logical actions and reactions than Inventor but I am slowly getting used to it.
One thing that I have to also mention is file management.
Inventor positively litters your hard drive with files and directories. It's bad. Really bad.
It is so bad that they had to add a "bundle and go" option just to collect everything.
TC Pro isn't that anywhere close to that bad and normally only saves one file for an item.
TC Pro also seems to be much more graceful when importing stl files (using the Pro Platinum version anyway), igs. stp and other common exchange formats.
But that said, neither TC Pro or Inventor will allow you to do much with an imported stl model.
Both Inventor and TC Pro can import 2D sketches for extrusion.
TC Pro wins at this too.
So if you have some really complex shape, just sketch it in 2D and import it.
Finally, there is the cost.
This is the 800 pound gorilla in the argument.
AutoDesk has moved to an annual subscription model.
They used to sell Inventor licenses for around $7500-$10,000 depending upon the add-ins you got with it.
Now it is about $1800 annually (gasp) with no purchase option.
However a "purchase" from AutoDesk always was mostly theoretical.
I personally own an older AutoCAD license (paid from my own pocket) but you think that matters or that it would give me any credit toward newer versions?
Not a chance.
A 2017 TC Pro license is about $1600 (one time cost), which is considerably less than I paid for AutoCAD at the time.
But if you are not needing to design large buildings and things, just buy regular TurboCAD for around $150, it will do just about anything you need for a 3D printer.
I paid $400 for last year's version of TC Pro Platinum through the link I posted earlier.
A proverbial no-brainer for my situation.
I will become more accustomed to its oddities as time passes.
But your experience with it may vary.
They do have trial period downloads and there are loads of YouTube tutorials and training.
Try them out, they are free.
That was what drove my decision in the end.
I do not regret my purchase in the slightest.
I hope this helps.