A Home Despot unit is as good as any other, same filters and RO cartridge. If you cannot do the install yourself, then PLEASE do not attempt to work on your guns.
I'm going to disagree - many of their units use proprietary components. I usually recommend either going w/a Sam's Club or Amazon system. Filters are relatively cheap - it makes no sense for me to try to market them to my customers simply for a few extra bucks - I'd rather help them find a cost-effective source.