Reddit reviews AILIBOTE Google Pixel 4 XL Screen Protector, [3 Pack] 9H Hardness Anti-Scratch Full Coverage Tempered Glass Screen Protector Film for Google Pixel 4 XL

Man, I just did this a few weeks ago. I got rid of the DVD drive and moved the 1TB HDD that it came with over to where the DVD drive was at and installed the Samsung 850 EVO 500GB SSD where the 1TB drive is now, that's because the connector where the HDD is now connected to is SATA III vs SATA I where the DVD drive is at. In other words if you want to better speeds remove the HDD and put the SSD in, then if you want the extra storage space (1TB) remove the DVD drive and put in the HDD there using a caddy.

I found myself needed the DVD drive ZERO (0) times since I've bought the laptop but everyone is different. By the way I highly recommend upgrading the RAM as well, it cost an extra $58 but it's totally worth it. My laptop, fully loaded with Norton 360, Office 2013 Pro, Adobe Acrobat X Pro, and all my other programs boots up in about 7 seconds. Here is the parts I used..

USB to SATA III cable

RAM

You need a T5 screwdriver to remove the screws to get into where the components are, I bought this set because it's handy for other things as well. BE CAREFUL WHEN YOU LOOSEN AND TIGHTEN THOSE SCREWS, THEY STRIP EASILY. Don't tighten them like the lug nuts on your car, TRUST ME!
Just use the cable and the software that came with the SSD to migrate the OS over from the HDD to the SSD, it's that easy!! If you want I can find the caddy that I used to replace the DVD drive, mine fits perfectly but I had to buy 2 because the first one was the wrong one. The outer plastic shell would not fit on the first one, but the second one fits perfectly. I can even post pictures showing you where the parts are located once you open the laptop.. Let me know, and I hope this helped!

*Edit - Found the Caddy

People can be incredibly picky about keyboards in reviews. Most of the reviews I've seen have been great about this machine. Not sure where you're getting the bad?

You can easily upgrade the HDD in this to a Crucial M500 without breaking the bank.

Throw this in the optical drive bay, and have 2 drives if you don't need the optical drive (most don't).

http://www.amazon.com/SanDisk-Plus-120GB-2-5-Inch-SDSSDA-120G-G25/dp/B00S9Q9UKS

http://www.amazon.com/gp/product/B00FWOR638?psc=1&redirect=true&ref_=oh_aui_detailpage_o06_s00