almost 3yr on my X52 Pro.
* no calibration problems at all (Pro uses beefier sensors which work great),
* trim wheel input kept dropping off to nothing (annoying as I use it for rpms) but new PC sorted that (the dreaded X52 USB power draw again I suspect),
* detents on throttle kind of broken - dont latch properly but theres still just enough of a detent to make Mace's WEP/Throttle/Engine off settings work (
)
compared to the logitech 3D pro I had before (lasted just 6 months btw), stick is muuuch smoother and more accurate. I like it 
Wrongo... the X52 and the X52 pro actually use the same exact hall effect sensors for X/Y, and the same pots for throttle, slider, and Z. The difference between the two is the double spring, and the X52 pro has more metal.. and a more programmable multi-function display. I'm not saying the X52 isn't inferior to the X52 pro, but they are not at all different as far as the internals go.
As for those with calibration/power issues. Yes a powered hub is recommended. This is NOT a big deal, and can be gotten online for less than $10, and in a store for less than $20. If that is even too rich for your blood, then you can adjust all the LED's down (or even turn them all off) and the stick will use only a fraction of the amount of power. Also the cable that connects the stick to the throttle (PS/2 cable IIRC) can become loose in the sockets and not want to stay in, especially if you unplug these often to put the equipment away.. or if you keep jamming the base of the cord against a wall/desk/leg.. who knows. I personally had no problems at all with mine, but I can see how it could happen.
I'd be willing to bet that 99%+ of people with 'calibration' issues on these have it because of power issues, or a loose connection. These are hall effect sensors with no moving parts... so for the most part it's either going to work or it's not. If it's losing calibration it's power related. Period.
Yes the spring is a little bit loose. Some people like this. I personally stiffened mine up a bit (X52 NON-pro) by cutting out the center portion of a CD, cutting a slit in it, and shoving it in between the top of the spring and its seat. This stiffened it up at least 25%, but I ended up taking it back out because the stiffer spring was making the center 'catch' area more noticeable.
In the 3+ years I owned my X52, I never had one single problem except for one single occurance early on when the computer didn't see my stick. I don't know what happened... I unplugged it.. rebooted.. plugged it in and then it was fine. Shortly after I purchased a powered hub (for other reasons.. I wanted more accessible USB slots and getting a powered hub just made sense to me) and have been running the stick through it trouble free all this time.
I love the way it feels, and I love the positioning of the buttons.
OK now time for the bad. I don't feel that the X52 is the most precise joystick out there. I had to scale it to minimize fine-tuned controlling of the plane (such as gunning) and even then it just seemed like I was overcorrecting myself all of the time. After about 3 years, it started to develop just a tiny bit of center shaft play.. not much.. but just enough to become annoying which doesn't help with this problem either. Also, when transitioning through the 'center' position, you get a 'notchy' feel as the spring unloads and then reloads as you move it the other way. You learn to overcome this by trimming the plane slightly left or right and then you are giving it a bit of left or right roll input to compensate... this way the spring is never 'centered' while you are dogfighting.
With that being said I recently replaced my X52 with a Logitech G940 (knowing good and well the negative aspects of this new stick, but I got it for a price I couldn't say no to). While I feel the X52 was much more comfortable and easier to use, I can't get over how much more precise the G940 is, ESPECIALLY considering it's a Logitech product. Its accuracy makes my X52 look like a child's toy, and this is with having scaling completely turned off. If they end up fixing its FF and reversal bug issues with the next software revision, I will be ecstatic! My fighter ability has improved AT LEAST 50-60% with this new stick.
So.. in general.. I would give the X52 3.5 out of 5 skuzzies. I have no experience with Thrustmaster... and my only CH experience is with an old stick of theirs from 15 years ago and from a flight yoke of theirs about 10 years ago, and I was not impressed by either... but I cannot judge their products today as a lot can happen in that time... and I cannot compare the X52 to either of those.