I am a relatively new Xoom owner...
The transformer has better support, screen (IPS), updates, and suffered from less general woes than the Xoom. The Xoom for the longest time had a screen buffer issue which would make things stutter. A lot of the same arguments can be made for the tab 10.
Now you could argue that a lot of this is down to the fact that the Xoom was out first and was the first 3.0 tablet which is a fair comment but once the rest came out Motorola pretty much all but dropped support for EMEA and Asia for some reason on what is considered the "pure" 3.0 experience.
It's not a bad device and you certainly shouldn't feel bad about it at all, it's just that Motorola made a bit of an arse of it and the "opportunity" to win hearts and minds with a killer device was lost. If you think back to how Samsung and HTC support their phones (which in all honesty, is very good) and then you think about Moto, it's not hard to see why there are some miffed faces.