I use Peak Vantage Spashett signiture motors for obvious reasons
I have Never had troube soldering a motor in as long as your iron has a 5mm+ tip so it can retain the heat.
As for them not being as fast as Checkpoints what a load of bollocks, my cars are never slow, and rarley is there someone quicker down the straight.
In my 4wd I get 2 meetings before I skim the armature but the brushes don't get changed for 3-4 meetings, and I get 5 meetings out of one in my 2wd.