I cook ribeyes on my traeger Jr all the time. Big ol thick suckers from Costco. I cook them at 160-180 till they get to about 120. Then I crank up the dial to 400 and watch closely till the center of the meat hits med rare. Then I take them off and let them sit for 10-15 min. The taste is incredible. I have also cooked prime ribs at 160-180 till med rare. Mmmmmmmmmmmm tasty.
Hamburgers cooked at the 220 temp for a while then at 350-400 till done are also really yummy. Slight wood flavor to them. If I need to do high heat searing and want the super grill marks I use my weber genesis. A great forum for the traeger is Pelletheads.com. Tons of very good information there.
One valuable thing I have learned about the traeger is the brand of pellets. The Traeger brand are actually my least favorite. Little flavor and don't burn hot. Last summer I got 3 huge bags of bear mountain pellets from costco. Burned thru them last summer and really liked them although they produce more ash. Not a big problem because I clean out my burnpot every cook. That is KEY. Really get good temp control and good smoke with a clean pot. If the pot fills up too much with ash, the smoke is very thin or non existant. Also the temps are all over the place. I just got a 50# bag of a special blend of pellets from cookingpellets.com. These are fantastic but were too expensive to buy again. Go to Pelletheads and start reading all you can. Vast information and all kind of needed to get the traeger to work its best. I go through about 100# of pellets a year on my Jr. I cook everything on it.