Just picked up my DB yesterday. Like you, I was torn between the Rectec standard version and the GMG grill. The Rectec was much bigger and had the all stainless steel construction. The GMG DB, although smaller in surface area, still had enough room for four pork shoulders at once. Moreover, it was $300 cheaper! Add in the wifi, a built in food thermometer, as well as other features not found on the Rectec, and I was sold. What made it easy was there was a dealer 20 minutes away from me and they had the smokers in stock. Rectec would have had to ship theirs to me (add $150 shipping and wait time). I was able to purchase my GMG DB, burn it in yesterday and now am running my first smoke on it.
I'm already impressed. Both for the burn in and to start the shoulder at 6am today, the temps came up quickly. I love the programmable link to my iPhone where I was able to set a profile for the shoulder (150F for two hours to get some deep smokiness in and then switch to 250F until the shoulder reaches 195F). The great thing was with the profile, I literally programmed it in and then went back to bed!! Woke up three hours later and the profile had already completed stage one (150F/2 hours) and had automatically cranked up the temp to 250. Its measuring the food temps now and seems pretty accurate. I may not have needed the 2 hour pre-smoke as there appears to be a good thin stream of nice bluish smoke coming out of the chimney. Can't wait to see how it turns out in a few hours!
So far, I highly recommend the GMG DB. I paid just under $800 for the wifi unit, a 30 lb. (approx.) bag of GMG pellets and a custom cover. Again, Rectec was $300 more AND with a delivery charge of $150. They are having a sale right now through Labor day. Helped push me over the edge. Hope this helps!