i would actually recommend grippers over sliders. I've had both now and the grippers were smooth as ice, fast as hell, and extremely grippy. They also have a bit of slide to them, and forward and fakie sliders are still possible. Powerslides are alot harder though. The only problem I could see with grippers is how quickly they wear down with manuals, etc. If you're still learning brakeless manuals you may want to find another wheel.
My sliders have a flatspot which makes them alot bumpier but they are also quite fast. They're good for tech guys yes, but also great if you're gonna be riding rough surfaces alot and they're actually better for rough surfaces. With my sliders at a concrete park I literally slipped out from turning too hard. Sliders are great for what their name is: sliding. If you do alot of fakie sliders or forward sliders or even powerslides, these will make them so much easier. The only problem you could have with these if a rougher ride or flatspotting the wheels, either from landing sketchy and slipping out or doing alot of slider tricks.
So... It's about personal preference but I'd say get the grippers.