The touchpad issues were only with very early models. Those sold after December are unaffected.
As for heating, the CPU can get up to 90C during heavy gaming, but that is still within normal tolerance for the i7 3630QM. The outside of the unit does not get beyond warm to the touch.
I attribute this primarily to the conservative fan profile that Lenovo put on it in order to keep noise to a minimum. The fan does not ramp to full until it goes beyond 93C.
Overall the unit is very nice and has a quality feel to it. The screen is average. It's not bad but not great. It's fine from direct viewing but is glossy and attracts glares easily. Viewing angles aren't great, but most people are looking at their laptop dead on anyway.
Speakers are loud sound outstanding. The keyboard is also top notch with cool red LED backlights.
It's very lightweight and portable. Some Ultrabooks are heavier. If you end up going SLI, there is nothing that even comes close in terms of performance and portability together.
I've found some pretty good value with Lenovo in terms of specs. However, you'll have to pray that nothing breaks or screws up because their customer support is a plague on the technological community. It took be a solid month to get a fix that eventually turned out just to be a faulty CPU. Dell, on the other hand, generally provides sturdy products with decent support, so it's up to you - specs vs support.
Laptop failures aren't too common. I would go with the Lenovo if I didn't personally hold a grudge against them.
^ Why so? Their customer support with remote assistance is pretty neat.
Dell will not allow you to update your video drivers. Customer service is pretty good.
(I have an xps 15 LX502 and I can't update the video card drivers because you need a dell certified driver. Unfortunately the last update Dell issued was over a year ago. Made games buggy as hell so I got a new laptop. Not to mention the thing overheated like crazy).