The one thing that a Brinkman Electric will teach is PATIENCE!
As long as your machine is hitting and holding 220ish with the lid on you are doing nothing wrong
A few tips that I know of are
Replace water in the pan with sand or use less water to try and raise temps
Start with hot water in the pan and allow the rig to come up to temps before adding the food to it
Use the smaller dryer chips and leave the door closed but not latched to allow flare ups that help raise the temps
Use the larger fist sized chunks to reduce the number of times that you need to add wood and open the door
Keep the lid on, no peeking and cut back on mopping until towards the end of the smoke
Check the smoker temp at the grill as close to the center as you can (I think that too close to the edge is right in the path of the thermal uprising inside of the rig)
Use a remote read thermo if you can to help reduce opening the rig. Or an oven type dial thermo setting on the grill, either that you have checked for accuracy (unfortunayly the dial read type tend to get smoked lenses)
You can do a few things to adjust the temps but remember that LOW and SLOWWWWWW is what it is all about
Read around for some mod ideas. I havent done it yet but I like Mikes idea about using bricks instead of lava rocks, I just use extra lava rocks right now but would like to try fire bricks or better yet maybe cast some refractory mix under the heat element. My biggest and favorite suggestion for a mod is to add more grates by using 2" 1/4-20 bolts for support brackets and letting the extra grills rest on them. (I am thinking or reconfiguring this concecpt to hooks or chains that hang from the rim of the rig so that I don't have to do the "Weave Obsticle course" getting the grills in and out) but that is another story)
Don't give up! But if you do, send that rig my way
Juuuuust kidding. I can almost gaurenteeee that a few more smokes will help you learn to love that little machine you have