Last fall I was looking into either a Trek Fuel EX or Top Fuel. I felt getting the 7 over the 5 in either bike was well worth price difference based on the parts specs and the few reviews I was able to find specific to those two models. As I recall, I think the 7 upgrades the fork, shocks, wheels, tires, brakes. The drivetrain is also an upgrade but that's probably the smallest difference (SRAM GX vs Shimano Deore). The EX7 should come set up tubeless, whereas the EX5 does not even have tubeless ready tires. I have the Shimano MT200 brakes on my rigid single-speed where they are perfectly acceptable but the MT410 will do a better job on a bike like the heavier, rowdier Fuel EX. Fox shock over the X-Fusion is a nice step up, too. And while I am not a weight-weenie, there is an over three pound difference between the EX5 and EX7 (2021 model specs).
I was not able to test ride either model since no demos were in the shops (friends were letting me test ride their bikes to help me decide what I wanted; that $5000+ EX9.7 was beautiful but way out of my budget 😁
. If you've never ridden a full squish for any length of time, you might not be able to discern much of a difference between the EX5 and EX7 in one test ride. If you do get the chance, pay attention more to the adjustability of the fork and shock. Also, be sure to ask the shop to set the air pressure and rebound on the bikes based on your weight so you are comparing apples to apples on your test ride.
My bike shop was also showing me the Fuel EX 8 which I would be fine with but don't know that I needed over the 7 (availability was an issue here, an EX8 was coming in in February, a EX7 or TF7 wouldn't come in until early summer).
All that said, the Fuel EX5 is a great bike and if that's what fits into your budget then have no worries. It's a really good bike and that $800 jump to the EX7 is easily enough to crash a bike budget. If you do go for an EX5, you might want to see if the shop will give you a deal on going tubeless with different tires and the full set-up before you ever take delivery of the bike. I've upgraded many things on many bikes over the years, most of which fell into "That's nice, glad I did it." down to "That was a waste of money." Going tubeless on my rigid SS and my gravel bike was the only upgrade that ever made my go, "Holy, shiest! Why didn't I do this sooner?"
PS: For my riding I was leaning towards the Top Fuel. Different specs and differences but I would still go with a 7 over a 5.
PPS: In the end, someone gave me a nice deal on an eight month old 2019 Fuel EX8 27.5 Plus.
PPPS: I have no experience with the Scott bikes. My LBS is primarily a Trek dealer. I also get a discount due to being on their team and volunteer hours at local events and trail building; so for me, going with any new Trek has a decent price advantage over other brands.