Yes the EZY A319's are weight restricted. I'm not sure but I think they don't have a centre fuel tank which severely limits their range. Also they are artificially restricted to save on navigation charges but different aircraft in the fleet have different restrictions. Some of EZS's A319's are restricted to 62T while at the other end of the scale, some of the EZY A319's have a 68T weight limit. The rest of the fleet fall somewhere in between. Structurally however, I think all of the fleet is near enough identical. That's why they use the A320's on longer sectors.