I have a Green Mountain Daniel Boone (med size) and the Davy Crockett (small one). Use the DB on the patio and the DC in the motorhome.
Just about everybody and their brother is now making pellet cookers (grills). Some are very very good and some are okay. The Green Mountain series seem to be one of the better bang-for-the-buck cookers.
The temp range runs from 150 to 500 (or better) and they now have a wifi unit available so you can control the temp and time from your phone.
Pelletheads.com probably has some of the best reveiws of all things pellet. Take a look and you'll learn all kinds of things.
With any pellet cooker there will be a learning curve from gas or briquets, but you'll shortly be turning out some of the best BBQ ever. Remember BBQ is low and slow (temp and cooking time) and grilling is hot and fast. Hence the pellet cooker vs just pellet grill. I've cooked everything from pork butt, veggies, bananas, steak, and even cobbler. This thing makes me look great. :)