The news never seems to be good on either side of the fence. Nvidia seems to scale like crud and AMD gets support late. That's why I have always ultimately decided just to get the fastest single I can afford at the time. But I certainly understand why you would want sli if you need 144hz or high res. Glad I'm not sensitive to these things as some users are. I guess I'm lucky that I'm easy to please.
For me, multi GPU would work if I invested in it because I don't play games anywhere close to launch date. I haven't played a game made past 2012 yet.