Hi DigitalMC,
Short version: I have the CW2900i and I would buy either of those stoves. If I could have gotten as good a deal on the Droilet I would have gone that route. The main difference I could decipher is that the Droilet has a different blower. According to SBI's customer support the Droilet has a different fan assembly and blower which has a thermodisk that automatically turns the blower on and off. The CW2900i has a simpler blower which is either on or off. The outer shells may be different too. Also, the trim piece that covers the fireplace opening is included in with the CW2900i but you have to pay for it with the Droilet. FWIW, I don't even use mine because I like how it looks without it and I think it heats better too. Someone else on here said that too. YMMV...
Long version: I installed a CW2900i myself last year after buying it from Northern Tool for $999. I had it shipped to the closest store to me for free and had them load it in my Honda Odyssey. It took a little muscle to get it out as the beast is 400 lbs. but I got it installed with a liner from Rockford Chimney Supply and was extremely happy last winter. I have an 1800 sq. foot house with a heat pump (thermostat on second floor set to 68) and two fireplaces. It's basically a four over four layout with a den and garage. Den is behind garage, has two exterior walls (exterior 15' chimney; raised masonry hearth) and only a 33" normal door opening into the kitchen/dinning area.
I'm in Charlottesville, VA so not the coldest locale but we have proper winters as we are at the base of the Blue Ridge mountains. That being said, my heat pump never went on until I stopped using the stove. I had great wood and loaded N/S 90% of the winter with great effect. My splits had to be 16" or less but most of them were. I burned mostly White Ash, a little white oak and a bunch of Eastern Red Cedar that was dry as a bone. I love that stuff. That was mostly my shoulder season wood but even so, that den was about 78 degrees and the kitchen was about 71. Yes, it was hot in the den but the rest of the house was quite comfortable.
I burned 24/7 for weeks at a time and only loaded the stove three times a day during the work week; when I woke up (full load), after work couple of splits if need be and before bed (full load). I do NOT have a block off plate either. Even though the Century Heat installation manual says to have one and their tech support/customer service recommend it (they are great by the way) I just couldn't get it to work with my fireplace. I installed the stove first so it was a huge pain in the but to try and bend the sheet metal etc... so I just said the hell with it and honestly, I don't think I need it for my environment. I also sealed my attic with spray foam in the summer prior to having the stove put in so I am probably retaining a lot more heat than I am wasting not having the block off plate.
Bottom line, these are great stoves. They are basic, not very fancy but I just couldn't spend another $2000 for the Hampton or Pacific Energy that I wanted and I wanted a secondary burner because I like to watch the fire show. I would always have about two hours of great blue and purple secondaries in the evening and I would just vegetate on the couch and watch the show after I put the kids to bed.
I hope that helps you make a decision. Lastly, the ability to burn N/S was a big plus when I was making my decision. I'll probably have to trim some of my wood this year to be able to fit my splits N/S but the benefit WITH THIS STOVE, was that I was able to burn wide open for about 15 minutes and then shut her down gradually after another 15-20 minutes and then go to work and not have to worry about anything for 9 hours.
All the best,
Sean