I purchased the AquaticLife RO Buddie +DI a few months ago for my IM Fusion 20 and I'm happy with it.
The waste to RO/DI production is below average for a compact system but for the price, you really can't complain.
I hook mine up once a week to produce about 5 gallons of water for my ATO and water change which takes about 4-5 hours.
Also, prior to purchasing the unit, I had a run of questions and their customer service was incredible. Not sure if the same model was available when WiredWeasel purchased his unit but I'm assuming some changes have been made over the years.