I dont know the 2 generics but have run Genotropin and Serostim. Genotropin I ran for a year or so once and 9 months several times. Very good gh. It is faked often though. My experience has been that the Genos from South America are always real. The product from Greece and Turkey is often times faked. But not always. The Turkish and Greek counterfeit operations make incredibly accurate examples of real medicines. Their Bayer Primo(Rimobolan) is as close to mirror image as you'll get. Same with the Genos. If you get real Genos, they are good. You will hold less water on them compared to Serostim and you'll be able to tolerate higher doses.
I've run Serostim for the past 2 years. Serostim is not available in most counterfeit countries so it is almost never faked. Ive actually never seen it outside of the USA and it is the only brand prescribed for AIDS patients here in the USA. It is the strongest gh I've ever run but also the most expensive. Due to it coming from US pharmacies. If you want to grow and put on mass then Serostim is made for it and I'd say the best gh for that cause. I would say Genotropin is milder and would be better suited for anti-aging purposes. Stronger is not always better when it comes to gh though. You'll hold less water on Genos. For me, that's better most of the time. I'm stronger on Serostim. Sometimes that's better for me but I don't like holding water and Serostim tends to come with a bit of water retention.