There's one Dell model that all of the hardcore Linux devs in the office use that I've heard called the rough equivalent of the MacBook Pro. XPS 15, I believe.
It is a great laptop and cost effective for the 9570 right now, $1699 CAD right now with the coupon code: http://www.dell.com/en-ca/shop/dell-laptops-netbooks-and-tab... I have a larger SSD and memory sitting around the office, so I don't count that in the cost.
I think it varies a lot between models.
Yeah, we can blame Dell a bit for this, but Wifi drivers are a problem for a lot of systems.
Replacing the fan may be worth a try, too. Google for the service manual for your system which will give you a step-by-step instruction guide with pictures, and the parts are easy to come by.
Still can't help with the coil whine or the trackpad, though. (Though generally I've heard people say it's the best trackpad outside of Apple. I can't speak to that, my standards for trackpads seem to be relatively low compared to a lot of people's, because I've been content with a lot of trackpads that the consensus says are bad.)
The trackpad is a nightmare. The bluetooth adapter randomly dies and I'm forced to restart. About 10% of the time when I close the lid the laptop doesn't actually go to sleep, but instead gets extremely hot, which is worrying when I take it out of my bag only to realize the thing has run down the battery and nearly melted. The list of issues goes on and on.