Have $500 to invest, which one is better for 2018
Waves or Stratis
Imo, Waves could be next dash.
I also think that splitting is the best solution, especially right now. If you haven't made a decision yet, buying both at such a good price is ideal. Both are two different but very valid projects, they have a good team behind them and I'm sure they will give great satisfaction. You just have to have patience on both and it will worth it. Good luck!