I'm sure it works fine in the end. Aquasafe has been around a while and I remember a few years ago when they first came on the scene there were a ton of Canreefers buying their units. There has to be some reason they're cheaper than average but I couldn't tell you what it is. As long as it's working and not leaking it's providing function.
With that said, I do notice they are using 100gpd membranes and not 75gpd membranes. While it might sound better because "oh hey, 25gpd more must be 25gpd better", it's actually not a huge difference in terms of the flowrate of water being produced, but in general, the 100gpd membranes tend to have a slightly lower rejection rate than 75gpd membranes. If say, your input water has tds 170, and the 75gpd outputs 1 tds (just say for example, I don't know the actual #'s) and the 100gpd outputs 2 tds, although this doesn't sound like much, you will go through way more DI in a year with the 100gpd unit than with the 75gpd unit. And the cost of that extra DI will be more than the difference in price of the membranes... So if cost is concern you want to pay more attention to the posted rejection rate over the actual gpd ratings.
There's a little more info in these two links:
http://www.bulkreefsupply.com/75-gpd...w-filmtec.html
http://www.bulkreefsupply.com/100-gp...-osmonics.html
They talk a little about rejection rates (98% vs 96%) in the descriptions of each.