In my opinion most cases just ad bulk and I have tried many. I'm getting a zippered sleeve ideally with an extra pocket.
The updated manvex case that I use is great. Not too bulky, not heavy, just right. I'll admit there are a few occasions when I take my device out, but honestly, there's no need to. The manvex case provides everything you need. I will say, though, that with a cover attached, the device is heavy. Without a cover, and just the Surface and case, it's fine.