The only differences between the SR1 and SR1+ are the + has slightly better fets, faster motor limit and comes with a fan. As far as features (timing ect) are concerned they are both the same, you can plug the fan into the SR1 too if you want.
I run an SR1 in my 2wd with a 6.5 V2 without a fan just fine, you'd be better with the fan in 4wd/shortcourse with big motors.
I never really play with the current limit on my Vampires, they are smooth/drivable enough I've never felt the need to
