I've had one for 6 years on my 40 gallon. It does well, but there could be better technology out there now. Use the MaxiJet pump, not the Rio.
I see there is a new skimmer out there for a 50-100 gallon tank: AquaMaxx Hang on Back Protein Skimmer. There is another, recent skimmer that uses one pump to feed the skimmer and another pump to make the foam (that got good reviews); I can't remember the name.
Unless it is used for about $75-100 then do not buy. The are horrifically overpriced for what they are and the are not efficient and skim poorly. I do not recommend HOB skimmers as they are expensive and less effective (the remora especially). What size tank are you running?
I've been using my Remora for 2 yrs now It works fine I need to dump and clean the collection cup twice a week. It picks up quite a bit of gunk, But this is the only skimmer that I've owned and do not have anything to compare it to.
I use it on my 55 gallon w/a maxijet 1200
U-tube overflow and add a sump. Possibly drill the tank with a glass-holes modification. Sumps do not have to be fancy, they just have to hold water and equipment. With larger capacity tanks, you really need to go with a sump (it will make life much easier). A Remora Pro did not do a good job on a 40g system and all HOB skimmers are a stop-gap (expensive at that) for your system. Check out my skimmer threads linked into my signatures below. In-sump skimmers are more effective and cheaper. The only other option in my book is a Tunze... and those are in-tank skimmers. Maybe a HOB SRO-1000... but that is just a cone skimmer but check it out in all of its red glory (btw, the in-sump version is $75 cheaper and likely more effective. http://www.aquacave.com/super-reef-octopusbr-xp-1000s-cone-hang-bron-back-protein-skimmer-2995.html
The main problem with HOB's is the same thing that impacts any skimmer that is placed in a poorly designed sump. Varying water levels are the problem and it will make even the best skimmer a poor performer. An ATO is a must for an HOB skimmer.