I have the same unit and it works like a champ. It will hold a rock steady 250* grate temp all day/nite long. But only 250*. You're gonna be hard pressed to get anything higher than 275* out of it and that's on a hot summer day.
Now...with that being said...here's what I learned along the way.
These things do NOT like the wind at all. It's only a 1500W burner and it needs all the help it can get. Build yourself an inexpensive wind shelter if you have the means to do so. (It greatly helps). Winter time...if you're in the northern region...build a shelter.
Don't bury the element in lava rock. Just don't.
Ditch the water pan and just use a pizza pan as a deflector. Otherwise...drippings will flare up on the burner. The water pan CAN be made to work..but you need to put as hot of water in it as possible...AFTER the smoker has come up to temp.
Put a good therm in the lid. It'll give you a good idea of your dome temps.
Plug it directly into a socket if you can. If not... use a medium to heavy duty extension cord and keep it as short as possible.
Don't over-crowd it with food. There needs to be air space around each piece of meat to let the heat work correctly...not much space...1/2" is plenty.
No peeking! Every time you lift that lid....it takes several minutes to get back that heat you just lost. Remember...it's only a 1500W burner.
I've had mine for over 5 years now and I treat it poorly...leave it out in the rain...don't cover it....bad me. But.....it's still on the original burner.
I've made some incredibly delicious baby backs, spares and pulled pork.....many many times. When I take my bbq into work and give it away in the breakroom...it's gone in less than an hour. They have no idea that it was all done on an electric Brinkmann.
Don't give up,brotha. That little electric smoker will turn out some amazing bbq....just gotta know it's limits.