I have NI Groove Agent, XLN Addictive Drums 2, a handful of other "drum machine" VSTs (because they're like Pokemon, you have to catch them all, right?), the built-in stuff that comes in Ableton Live and Cubase Pro, and a Roland TR-8. For "quality" sounds, Groove Agent of Addictive Drums win. For "just lay down a foundation to jam along with", the TR-8 wins hands down. Several years ago, though, Roland superseded the TR-8 with the TR-8s, which has some different functionality. Never bothered to "upgrade" because what I have works for what I want to do with it.
If I'm building a track, the work flow, generally, is to just get that four on the floor going with the TR-8 and then eventually replace it with better sounding/more complex MIDI patterns from Groove Agent. Just depends on how much effort I feel like making at the time and whether I'm truly "building a track" or simply "futzing around", aka "noodling."