One needs to consider the trade offs between portability and capacity. I was going to get a midi, but after comparing the different models, I went with the CT36 as I wanted not to have to empty it as often as a smaller unit. I am a hobbyist and don't have to move my extractor to job sites where weight and portability are an important factor. I just filled my CT36 for the first time and it was quite heavy when full. The filter bag must have weighed 20 lbs when I removed it, but was filled mainly with MDF dust.
I mainly use a tracksaw and router with mine along with sanding. The CT 36 with the larger 36mm hose is the perfect ticket for my use, but if I needed portability, I would likely have chosen a midi. In any event, these extractors are worth the price in my opinion and the 15% sale pushed me to act.