Indicas tend to hit me harder than sativas. Indica is a heavy buzz, you never forget that you are stoned. Sativas are more subtle, generally, though there's nothing subtle about the impact of a good Colombian or Mexican strain. Sometimes I think a sativa buzz has worn off, then I start laughing at something weird and realize I'm still pretty spun. I think sativas tend to be more hallucinogenic while indicas are more sedative. Sativas are more likely to give you "brilliant" inspirations, I think, but also paranoia. If I'm having a lousy day and feeling all wound up, I'd probably pick an indica over a sativa to medicate. If I know I need to stay awake for a long time, I'd go with sativa.
A couple weeks ago I had some so-so indica bud and some sativa that was also middling. I decided to put them both in the vape and was pleasantly surprised. It seemed like they were much better mixed together than by themselves. But of course, anyone else's mileage may vary.