Well i've used one+ (which is essentially the ame as S1+ just more of a lotion) and LGP 1-T HydroxyTest. I used the one+ for a short cycle of 2 weeks (I strained my lower back but had planned on a 4 weeker) and gained 10 lbs. This was my first stack. I used the LGP brand for four weeks (my third cycle I believe) and gained another 10 lb. The one thing I liked about one+ is that it smelled much better than the S1+. The 1-T OH has the addition of hydroxytest though. The best transdermal I used was the T-gel in my opinion. It had the best texture, the best smell and was reasonably priced. You can make your own S1+ or 1-T OH over at powernutrition.
So my conclusion is they are both effective. You just have to factor in price and whether or not you are willing to use a spray or a lotion.
Hope this helps