I went up a size for the away kit this year, based on what others had said, and it was definitely necessary. You'd need to be a skelf to get into the sizes they're pitching.
On the whole, though, I think Joma have been great. Certainly the designs they've given us are much more bespoke than anything we'd had before. A lot of that credit has to go to those at the club who drive that, but Joma are much more willing to engage than the likes of Puma etc where you're getting glorified teamwear.