I'm not sure this will solve your problem though. I mean, I absolutely understand where you are coming from. Believe me, I've had the feeling at times as well. The whole "why don't I sell what I have, take the loss and buy something that works" feeling. And then you buy something and within days, sometimes weeks, you will have something that will need changing on your new machine. And that is where it starts. Before you know it there are things that are not working as they should anymore (obviously by no fault based on your changes)... But that is what happens. And before you know it you are back to square one.
But go ahead and get the TU250, just don't sell anyone yet.