I would choose Waves over Stratis. Waves has some good updates coming out in Q3 and Q4 of this year. Stratis has been declining for the last 2 months. Or you can split and buy both.
I am also equal to you, if I have to choose the waves or stratis I will choose the waves to be my investment in Altcoin, because the waves are better than the static. You can see the waves in Bittrex with a very good selling point in the market.