I'm the sole remote player in a group. They're in Chicago, I'm in western PA. We use MapTool, but the specific tool is irrelevant.
I'll start by saying that I enjoy it very much; we've had basically no technical issues with the VTT side, although there have been the occasional sound issues which we are trying to resolve (specifically, when using Ventrilo, lag would predictably increase from zero lag to about 30 seconds, at which point I'd have to log off and back on to reset the lag; this cycle repeated anywhere from within 5 minutes to over the course of an hour. Skype made this a lot better in our last game).
The group in Chicago uses an omnidirectional mic (designed for teleconferences) and so it's pretty easy to hear. With Skype, the sound levels dropped off now and again (things got indistinct) but with Ventrilo, it could get deafening, so I prefer Skype since it didn't lag and I could ask what was said.
As far as interaction goes, that's where being the remote player is noticeable - it's much less spontaneous; laughing at a joke (especially with push-to-talk active!) sometimes seems weird because I'm not there. I also sometimes miss side chatter that might be relevant to me, and they all share one mouse and keyboard so there's not a lot of chat communication going on. It means that my interactions are more limited, less spontaneous, and often more focused on mechanical gameplay than roleplay. Also, I miss the occasional nonverbal cue (we don't have video capability). The only other technical issue is pretty obvious - if my internet service drops out, or there's a storm and the power goes out, then suddenly, I'm no longer there. That's thankfully quite rare. However, overall, it's good, and everybody understands and attempts to make sure that I'm not missing anything just because I'm not physically present. It's just a little different.
On the issue of Do Not Disturb, our game takes up a 4-hour time slot every Sunday. I play at the computer in my bedroom, but it's so I don't disturb others. If my family needs me, then I excuse myself from the game to attend things. It doesn't happen often, because there are few situations that genuinely require my attention*, but sometimes I need to step away, and that's just how it is. So my feeling is that this cannot be inviolate time; your attention is not undivided in this situation.
* My wife is of course completely competent to handle anything and even when she's not there, my kids are self-sufficient and only fetch me for emergencies.
