Since my 30 window has now expired, I just wanted to update this post to let everyone know that I decided to keep my SP3. Though I still have some reservations, this really is the best device for ME at the moment.
After last week's firmware update, things do seem to be running a little cooler and with less fan. I did have an issue yesterday with Metro IE. It was the ONLY program running, had only 1 tab open, and was browsing Craigslist; pretty light duty stuff, if you ask me. Within 30 seconds, the fan started up and increased in speed and noise until it was pretty darn loud, although heat was not too bad. The CPU was up around 45% according to Task Manager and dropped to 0-1% when I closed IE. I also still have some other pauses/hangups with other apps, but I can live with them for now.
I still think MS needs to pay some attention to ironing out the little problems; despite some of the people on this board discounting them just because THEY don't have them, the heat and fan issue is real, whether it's by design or not. I'm not looking to rehash that debate, I am just speaking from my own personal experience. Although I think the device is far from perfect, it is the best device of its kind right now. For my usage scenario, a laptop is not an option. For someone who relies solely on a laptop or tablet, I'd pass, but I am someone who needs both, so I think the SP3 lives up to the hype.
I am cautiously optimistic that the SP3 will get better as time goes on and MS keeps up with issuing updates.