I've had a pellet grill for almost 2 years now and I really enjoy mine. I've smoked briskets, 20 lb turkeys, ribs, Boston butts for pulled pork and I make great ABT's on it. Of all the "smokers" I've owned, the pellet smoker/grill has been the easiest to use.
Couple of things I've learned in the process: When buying new pellets always make sure they don't use fillers (mainly Alder wood) mixed in with whatever smoke flavor you use. This mainly applies to the lighter flavors like peach, apple or cherry. Traeger, LumberJack, Rec Tec, Camp Chef are all good brands of pellets. My favorite is CookinPellets (Amazon $36 for 40 lbs of 100% hickory pellets or a Wood mix of hickory, Maple, Cherry and Apple)
One of my biggest initial disappointments with the pellet grill was that I could not get a great sear/grill marks on steaks (my pellet grill/smoker can get to 600 F). I then started using a product called GrillGrates. They are anodized aluminum plates that you put on top of the normal grill grate. They are awesome. They actually get about 150 F higher than your grill temp (I measured mine with a laser surface thermometer). You can get them individually or in multiples since they slide together for a larger surface area. They are about 5 1/2" by whatever width of your pellet grill drip plate. I use 3 of the 5 1/2" by 13 3/4" and can put 4 nice ribeyes on them. They also make round plates for round grills.
Biggest drawback. If power goes out you are screwed. Pellets can also get expensive (about a dollar a pound). I cook a lot on the pellet grill and I go through about 10 lbs every 1 to 2 weeks.
Also, the little bucket that comes with most pellet grills to catch drippings is worthless. Mine has almost overflowed when smoking multiple butts. Go to Home Depot and get and empty gallon paint can and a lid and use it instead. At the end of the year you just put the lid on it, throw the can away and start with a new one.

This post was edited on 3/27/17 at 3:16 pm