While I wouldn't put it in the same group as Dead Rising and stuff like that, for me it was a joy, the start IS slow, too slow for some people maybe, but it didn't take me* long to get to a point where I could capture camps, and fight groups of zombies without trouble. Once you get to a certain point where better weapons become available it gets way better, and there are some really powerful weapons out there, also, your bike can carry more ammo, and once you max out both your bike's pouches and Deacon's ammo capacity you can take on several hordes without worrying about running out of stuff, healing items are also pretty abundant, as are grenades and traps so it never felt as slow or as survival-horror as TLoU, nor did it feel like I should try to avoid combat or that I was at a disadvantage, if anything, it was usually the opposite, specially against human enemies. I would put it somewhere in the middle, between DR and TLoU.
If you don't mind some light spoilers, I'd suggest looking up some videos on hordes, those are the highlight of the game, and going from running for your life at the start of the game, to actively hunting them is great, specially when you get the Chicago Chopper.
*Disclaimer: My copy of the game came with the pre-order code which unlocked the drifter crossbow at the start, it is silent, accurate and a one-hit-kill on most enemies, it also included an upgrade for the fuel tank, playing normally, it takes a bit longer to get this stuff.
Thinking about it, the best way I can put it is:
TLoU is like drone-ish doom metal, Days Gone is death metal.