Hi Morgan, I just bought a Y510P off of Amazon. I've been laid up the last week with a knee injury and thought it would be a good time to start looking for a new laptop. After scouring the usual sites, I had a spreadsheet with about 8 or 9 laptops around the $1000-$1200 range. I narrowed it down to the Lenovo Y510P (4700MQ, 2 GT 755M in SLI, 8GB, 1TB) and ordered it earlier in the week. I got it yesterday and I have to say that it's not perfect, for $1050, it's a heck of a machine. I have a PC that I game with as well, this is more for when I'm away from it or I need to edit video on the go. So far, I've haven't had any of the common issues with SLI (perhaps nVidia drivers have finally gotten SLI down). The performance is brilliant, fantastic Haswell CPU, brilliant display at 1920x1080, unbelievably wonderful build quality. There's a few downsides with the laptop though: mainly, having two GPUs means that the heat output is on both sides of the laptop, and while gaming (I've only tested a few so far such as Skyrim) it can be quite noticeable. The aesthetics of the laptop are nice (I love the layout and especially the red backlit kits), but I find that the lip on the front of the laptop can cause lines on the underside of your forearm. In my opinion, the 24 hours of I've had with it, it's certainly impressed me (far better than the G46VW I was using earlier) Of course as with all laptops, I'd always suggest wiping down the stock 8.1 and reinstalling yourself, Lenovo went a bit heavy with the bloatware this time. The last semi-con would be the clickpad. It's not terrible, especially if you prefer a tap click instead of the physical click, but it does take a bit of getting used to. The nice thing is the drivers support Windows 8 functionality which I think is nice. I had seen on some forum posts and YouTube videos that the Y510P's that don't ship with SSDs don't have the adapter, but thankfully mind does (in fact I'm here to find out the exact type of SSD that I'll need to fit) so I don't know if that's a new standard that Lenovo is doing, or I just got lucky.
So in a tldr format: For $1,050 with Prime shipping on Amazon, the Y510P is a great laptop with tons of power, great physical appeal, and a fantastic price --but a little too much heat output for my liking, bloated copy of 8.1 (but that's expected), and may or may not come with the SSD adapter.
Really, I like the laptop, and compared to what else is available, I think it's one of the best. Sorry for the long post, but I hope it helps you decide what to get.