It started out good.. It's too bad it reverted to bullet sponge as you kept playing. Lv1-5 was really nice. Enemies felt just right for normal difficulty, It was actually fun to play and you could flank and do whatever, instead of just sniper camping that ruled Div1.
But as soon as you get to lv6, it changes. The bullet-sponge starts and at max lv7 it's not enjoyable anymore.

cut-to the Invaded mission and max level.. that experience was horrible. full mag of 60 bullets and an endless headshot spree to kill a single red enemy? no thanks.
I don't understand that design decision..
Enemies bullet spongey-ness makes it pointless to try and flank enemies, since you'd be hard pressed to even kill a single flanked enemy, let alone his 2-3 friends that can easily shot you at this point, and usually if you charge/flank a lone enemy, it leads to a new spawn of enemies, usually spawning beside you.
There really isn't any point in doing anything but camping from a distance and everyone using the same Sniper Specialization..

Even if its a "cover-based shooter" I still want to be able to maneuver and use tactics. I don't want to simply camp through every encounter and just snipe.
With bullet sponge you remove all form of tactics. The only tactic that prevails is creating a bottleneck and focus fire/Snipe fire. There's no point in anything else. Where's the fun?

I don't get it. Div1's progression wasn't good. You need to make it better. When going through the world tiers at max level, maxed out in one world tier was horribly boring and going up to the next tier was god awful bullet sponge.. Stop these extremes please.
Using Destiny 2 as an example is actually really great, because their difficulty curve is actually good. the easiest enemies keeps scaling so low-end content is still enjoyable. it's not too easy and boring but rather fun, where as the new content for your level is challenging rather than bullet spongey.
Unless you're 5-10levels below the enemies, at that point it's pretty rough.

You're on the right track at lv1 through 5, maybe just add a taaad more health to those numbers and keep the percentages as we get higher.
Do something like ESO, make lower level gear obsolete rather than increasing higher level gear. you can explain it as something like wear and tear or something. Then use mods to make important stats and builds and weapons are something you just pick up and use up, than re-mod to another newly found weapon.
This could make it easier for people to get the weapons they want, because they'll wear down and become worse, meaning you need to get another one, which would increase the drop chances.
Idk, maybe it's a bad idea.. but at least keep working with the healths, because the current lv6+ stopped being fun.

Imo, you should just stop thinking about leveling up and increasing the power numbers. It's kind of a ****ty way of just getting players to chase numbers, rather than making a fun experience.
Taking destiny 2 as an example again. Most of the game is based on you doing the same amount of damage on the same amount of enemies, even though you're getting "stronger" gear. This makes you normal all the time, which makes the game world more alive and your characters more grounded.
Chasing the power numbers constantly makes you chase the normal and always feeling/being under powered. This isn't an enjoyable-state.. though I get why you'd do it. It should lead to dopamine addiction and keeping players around, but how about just making it fun and enjoyable instead?
Why do people keep playing Warframe? it isn't because of a power chase, it's game play chase. Altered gameplay through streams of weapons and frames with a constant normal is more fun and enjoyable than a negative cycle of power chase.

Thanks for the Beta opportunity. Hopefully my impressions will help.