Thinking of replacing my 17r1 with a 17r4 thoughts

So the title says it I'm thinking about replacing my 17r1 i7 4700MQ, R9 m290X, 16gb of ram with a new 17r4 i7 7820Hk, gtx 1070, 16 gb of ram, and the QHD display. thoughts pros cons I don't know a lot about the new r4's yet
I bought an AW17 R1 and was appalled by the terrible sound quality compared with my previous M17x R2. Besides which, after 5 months of ownership the R1 had never worked correctly so Dell took it back and refunded me. In June I purchased an AW17 R4 and there is simply NO COMPARISON between the R4 and R1!

For starters, the sound is unbelievable with an incredibly well simulated 7.1 surround sound experience coming from the speakers. The first time you play a game or watch a film that has 7.1 surround sound you will be blown away. The machine is far more reliable and games are handled beautifully. Some people have complained about stuttering due to thermal paste not having been applied correctly but I have yet to experience that.

Overall I am delighted with this machine. There are only 2 things that I do not like and they are only 2 USB 3.0 ports and 1 Thunderbolt port, and Windows 10 which I absolutely hate!!!

My advice to you is to go for an R4 or wait for a possible R5. The R5 or replacement for the R4 is likely to have the new Intel i9 processor but it will be far more expensive. Maybe Dell will go with the AMD version which is almost as potent but more affordable? Whatever you decide, I seriously doubt you will regret the upgrade.
The R4 is a nice machine. The main point to take into the argument is that your losing the ability to upgrade your CPU/GPU in the newer models and unfortunately there is no way around this if you want to stick with Alienware.

The newer R4 series has made quite a leap in terms of laptops GPU design using full on desktop GPU's now instead of watered down "mobile" variants. The only lesser GPU out there would be the 1080 MaxQ in the 15, which if your looking at a 17 won't impact you.

Temperatures can be a little trouble some IF you get a unit from the factory that didn't get a good paste job. This can be fixed a number of ways but calling support and having them attempt a repair is best if your not super comfortable taking a laptop apart as the process is a pretty good teardown for these machines.

If you want the QHD screen then I highly recommend the 1080 vs the 1070 as it will future proof longer and give you higher FPS for that sweet sweet 120hz display.