Hi,
We've used a few proface screens and i personally think they're quite good. Tech support is good in uk and there's lots of functions.
Depends what you want to do really. Some of the smaller lower res screens don't look brilliant but this may just have been a settings issue.
We have a customer whose machines use nothing else and they don't have any hard buttons on the machine whatsoever and they've not had any failures or problems.
We tend to use red lion screens more often though as they're much cheaper. Traditionally, i used to moan about the programming software (Crimson 2)when compared with GP Pro EX but now crimson 3 is out, it seems much closer to gp pro. Tech support from RL is good although tends to be better after lunch when Dan and Mike are online here (Time difference you see!!!)
Hope that helps.
If you want any further info, drop me a message.
Cheers
Paul