I'm starting to understand the 3050 'hate', as it was a really cheap / lame way of saying 'SUDDENLY EVERYTHING IS MORE BETTARRRRR' as every weapon / equipment was 'clan' so everything got "more extreme" with more lasers and more action and such. So I'm really not a fan of clans on that part, because the whole premise is flawed and silly.
HOWEVER, I hate most of the IS mech designs (whoever thought up some of them - it's like... 'Really?'), and IS politics themselves are dramatic and whiny. And the whole Davion thing is officially 'played out'.
BUUUT one of my favorite mechs (I really don't have a single favorite, it's one of a few that all qualify) is the Mad Dog. The clans made missile racks look COOL.