Hi - I've had mine for about 3 weeks, it replaced my 10 year old X-52. Seems pretty solid, the joystick spring system is similar to the X-52 but seems to have a plastic centre shaft rather than the X-52's metal one.
Don't expect to have any problems for a while though.
I feel that some of the switches on the throttle base (the ones forward on the right side) could have been placed on the joystick base which has no switches at all. The X-52 does have switches there so I still instinctively reach for them. In FS9/X I use them for less common functions like tailhook etc.
The joystick itself has more buttons available and three hat switches but the upper one is harder to reach over the top of the lower one (the grey one)
There are plenty of switches though - I'm not even using some for FS9 / FSX.
I noticed that the rotating wheel on the left of the throttle handles is not a rotary switch but acts much like a toggle switch - push it forward it switches and backwards it switches the other way - I use it for prop pitch - not sure what to do with the 4 rotary switches yet.
Also, I use the softest spring (personal preferrence) as the others seemed too stiff. Both units seem to slide around my desk more than the X-52 but that's easily fixable.
OK, these were just a few quick observations - there is a lot of personal preferrence with joysticks - if I had had a chance to actually try the X-55 before buying I would still have bought it.
Alan