Hey guys, my friend needs help with future upgrades for his iem. Currently, he has a pair of Westone 2 but he's tempted to try out the big 4, which are the:

Westone 3
Shure SE530/535
Sennheiser IE8
UE Triple Fi

Anyone has the Westone 2 before and upgraded to any of the ones above? He wants to know the benefits and most importantly, the SQ upgrade and whether it is worth the jump or not. Students with a budget. Thanks~