Trainwreck is very manageable. Very chill high, mild flavors. Great for relaxing with significant other or some friends. Mellows you out, with plenty of munchie feelings. This is my go to for a daily smoke.
Sour OG is, by far, the strongest strain I have ever smoked. Bar none, 1/5th of what I'd usually smoke will get me to average high levels. It is difficult to predict, but I always smoke as little as possible and get an incredible high. It's comparable to edible highs, when you've eaten too much.
I enjoy it but it's just hard to measure the appropriate amount.