If you like the EoTech...go for it. They are quality optic choices if that type of sight best suits your needs/wants/goals with your rifle. I tend to agree with some of the above posts re: using dot/holographic sights for a "precision" AR or for longer range work, but again, only you can decide if a non-magnified optic is best for your purposes or not.
If you want better functionality...skip the add-on @#$%&*!& trinkets at the beginning and start with something that will matter in terms of making the rifle shoot better, be more accurate, etc. For example, the factory trigger in every M&P15 I've fired just plain sucks!! They are gritty, heavy, sloppy and just generally pretty piss poor even for a mil-spec trigger. That'd be the first thing I'd do if it were my rifle instead of throwing good money after bad trying to make it shoot better or be more functional with forward grips and the like. Spending money on training and ammo is a much better use of your funds.
Now, once you have had an opportunity to field your rifle some and have a better idea of what you want/need for it, then the AFG/AFG2 may be a worthwhile consideration (again...depending on how you'll be running it). They do a nice job of allowing the shooter to keep a high grip on the end of the rifle, closer to the centerline of the bore (as opposed to way off center/low on a traditional VFG), and in doing so, they tend to make the rifle more controllable (in terms of pointability, perceived recoil reduction, more solid grip on the rifle, and increased speed on follow-up shots...again though...all of that is dependent on the shooter running the rifle right to begin with). Whether you go with an AFG or an AFG2 is up to you. The only real differences are the AFG is longer and takes up more rail space (length-wise...and height-wise/width-wise because of the wings which are absent on the AFG2). The AFG2 eliminated those features and changed the design somewhat to allow compatibility with a larger range of rail systems in conjunction with the use of additional rail accessories like rail covers, lights, etc. that may have otherwise not been mountable in the desired position because of the larger design on the original AFG.