as rob said i had a simular dilema not with electrics but do i upgrade by b4 to c4.1 or sell and buy a compleate mid/rear NEW kit
i went for a durango dex210 im very happy with it just to put into perspetive
b4
c4.1 conversion £159.99
c4.1 stiffners £28.49
b4.1 bearings £7.79
b4.1 outdrives £18.39
Total £214.66+Possible saddle packs HPI £59.99
Total £274.65
Sell b4 £60
Durango dex210 £194.91-£60=134.91
Schumacher SV2 £198.99-£60=138.99
Savox 1257 £56.89
for a total of £200 you would get a mid and rear motor buggy and a very good fast reliable servo.
stu
all prices from jemodels