quite a lot. but the testosterone will add water weight during the cycle. i would run the testosterone at a very low dose (~150mg/wk) and the winstrol at 50mg ED or 50mg EOD. keeping the testosterone dosage low and combining it with winstrol should prevent added water weight gain which would slow you down and reduce your vertical. be sure you have a decent PCT protocol so that you can keep your gains after the cycle is over.
you should see considerable strength and endurance increase as well as little weight gain (any weight gain will be pure muscle and not water or fat)
and winstrol has a bad reputation for causing joint pain and injuries, so be careful with it and i would get some Cissus quadrangularis extract.
Purely individual. It will depend on DIET, TRAINING, genetics,,etc..
Substantial strength gains are very possible with the TEST/WINSTROL stack if used correctly.