is blood actually as good as people think it is?

In my opinion, Blood deserves all the hype. The hitscanners in Blood are the reason I play Blood and removing them would be a terrible mistake. I can't play Duke Nukem or Shadow Warrior because while the realistic environments are cool, the build engine movement and shooting just feels very mediocre and the enemies are really boring. It feels like I could be playing Doom instead.

Everything in Blood is fine-tuned around the Cultists, and the rest of the enemies don't matter. The fact that cultists have very little wind-up time makes you play it completely differently from every other shooter which is what makes it fun. It's doing something different from the other shooters in that era. No other shooter can make me feel so frantic. The fact that you have a really high jump and can jump over enemies makes it very very fun.

The weapons in Blood are extremely reliable and useful against the enemies. In HL1, a game that is also notorious for very strong hitscanners, the HECU are bullet sponges. They take a couple shotgun blasts at medium range (If I recall, this may be just on Hard difficulty) and the MP5 takes forever to kill them. Your grenades are very unreliable if you aren't skilled at using them and they need a lot of setup time. Also, you can't stop enemies from shooting by making them flinch.

In Blood, your shotgun almost always can 1 shot cultists at close-medium range. If it doesn't, they'll almost always get stunned. Your tommy gun can stun an entire group of cultists if you spray around the room. Cultists in blood have AI that makes them stop shooting for a few seconds after flinching from damage. I think they also do this when bullets pass near them but I don't know. Your flare gun alt fire, dynamite, and napalm are also extremely dangerous, effective and consistent.

Most levels also give you a decent amount of health if you know the secrets.

I will say there are some bullshit rooms. The dining car in the train level is almost never consistent for me, you don't have the weapons and ammo for it most of the time. But once you get familiar with the levels, I think that even ep3 and 4 are really fun. After you start knowing the enemy placements a bit, you can start playing really aggressively. Jumping headfirst into a room full of cultists, explosions flying everywhere, everything is screaming. This fluidity is something that does not happen in Duke, Doom, or Half Life. Just watch this playthrough (E2M4 is a good example):