Tyros 4 weighs 32 lbs

PA3X 61 weighs 32.4 lbs

PA3X 76 weighs 38.58 lbs

The weight thing is no real reason to not buy a Tyros 4.

As for a lightweight ATA case with wheels here's one that is proving to be popular at 20 lbs!

http://www.synthzone.com/forum/ubbthread..._Als#Post330486