the hyper is about 1lb heavier (major issue) than the caster, and you may have to do some radio tray mods to get your elecs. to fit. i had a spectrum receiver and a hump pack all crammed into the tiny box with no on off switch and it worked fine. caster, nice big flat box. some people have complained of brake issues, i never had any. durability on the hyper is second to none (hope you are good with diffs). the new k8t's come with big bores as well as the old stock shocks for backups (jic). the shocks look like the jammin big bores but they use the clips instead of the pain in the ars threaded shocks. if you need to make an adjustment with threaded shocks it takes like 10 minutes all around to get it right, assuming they are clean already. or 4 clips in 5 seconds, done. caster parts are cheep and easily available online, most ofna parts fit in the hyper (lhs?) or you can look for hyper stock parts on ebay for very cheep (plcman1, good seller). i raced the hyper for 6 months with very good lap times, very few finishes, and a lot of fun. i've raced the caster 2 times so far (old blue version) and finally got the kinks worked out. its ready to do some hurtin'. i've been running the go 3 port race and this motor really impresses me very day. just when i think its running fast, i take a quick temp and realize i'm still under 200c, lean it a couple hours and its totally ballistic at 219c. awesome pop with good crisp acceleration and a rock steady idle, just awesome.