I am using Goku's at the moment, mainly for the SSJ4 capsule which I failed to get by being a moron and SSJ3'ing vs Kid Buu in the last fight. I think that with him it may be worth it becasue he has at least 8 capsule that can be very useful (5 trans + WK, SB and Kame, although the Last 2 are fairly redundant if you have the 10x Kamehameha in SSJ4 form, almost 1000 dmg for ->E...whoosh) and since the Breakthrough appears to count as each blast item being equipped twice (or whatever max times is) it seem to be worth it.
But for Chars such as Kid Gohan/Tien/Yamcha who have next to no individual moves I can't really see the point.
Like to know your opinions on these although I acknowledge that a lot of you will have given them up by now for the sparking!!!!!!!!!!!!!!!!!!!! cap or whatever number of !'s it is