Does reading poker books help or hurt your game? Personally, I find that in the short term it definitely hurts mine. Always has. My girlfriend has actually suggested that I never read another poker book. But, while it hurts my game in the short term, it does helps in the long run. No pain-no gain, I guess.
For example: In October I was playing well and winning. I won in 23 of my 28 sessions. I added lots of trophies, and increased my bankroll by more than 50%. But, I wanted to see if there was a more profitable way to play my draws, so I re-read Sammy Farha's book on Omaha.
What happened? I totally threw my winning style out the window and tried to play like Sammy. A complete disaster! Look, I'm not a luck-box that can conjure up four outer's at will, never have been, so the style that has always worked best for me is to grind. You know; pick up small pots, avoid coin flips, and try to create opportunities to get my stack in as a big favorite.
Even so, I'll admit that there have been times that I've watched an extremely aggressive player hit everything in sight and run their stack up 4 or 5 buy-ins in a short time. And similar to my reaction after reading a poker book, I have mistakenly attempted to switch and emulate their style on the spot. Usually with less than stellar results.
So while I believe that you should read poker books, magazines, forums etc., and even carefully watch players that give you problems. I also believe that you should be wary of changing your style on a whim, and that calculated steps should be taken to protect your bankroll when experimenting.
Let's say you have just read a new book, or have watched a player dominate your table. Drop down a level or two and try a few new things out there first. And don't just try it out for an hour, or one session. Test drive it for at least a week. Let it become comfortable. Let yourself grow into it. Learn how other's react and adjust to what you're doing.
It's important to be able to play as many styles as possible. Reading and carefully watching other's work is an excellent way to learn different concepts. But it's one thing to see or read about a style or technique, it's another to make it fit into your game. Don't just shove it in. Lubricate.
Oh, and as for those super agro-donks that occasionally come flying by? I've always kept track of the tables at levels above and below me to see who is moving up, and who is moving down. This lets me know which players are playing or running well and which one's aren't. Most often, you'll see the super agro-donks heading down.
Good luck and don't suck,