I like the survival aspect of it, but it can be a little daunting. You start off with just a pack containing painkillers, a bandage, and a flashlight. You're completely on your own finding weapons and equipment, and it can be hard. The most I've found so far was an ammo cache and some road flares.
I haven't run into any players yet, but you really can't underestimate the zombies. If you take one misstep around one, they'll be on you like stink on shit, and you can have a hard time losing them once you aggro them. It also sucks if you spawn a new character at night because the zombies appear to be attracted to the flashlight if you use it, and you can't see much of anything if you don't use it.
Now, there are also some glitches. One of the more prominent ones right now is a graphical glitch that I've experienced when there are a lot of buildings in my FOV, and it really limits how much you can see. I also just experienced a glitch where I opened a door, and when I tried walking through the doorway, I ended up with a broken leg with no way to fix it.
I haven't played the ARMA games past the tutorial, but you should still be able to play them even after you install Day Z. There are "launchers" that you can download that can easily turn off the mod and let you play the base games.