My single biggest hate is LACK OF MAP LEGENDS!!!
Followed by the lack of tool tips on vgps map tool.
It is frustrating trying to work out what some of the icon colors mean, and I am an experienced PGC user! It must be really bad for people new to the site.
On the other hand, PGC support are very good. Some things might not be on the priority list (such as my map legends) but generally fixes and updates are quite prompt. Well done Ganja1447!