They certainly seem a lot more capable than a lot of people give them credit for, and they certainly overcome the 'techno-babble' that puts a lot of people off setting up a marine tank, but they aren't without problems.
Mine has had new cooling fans, a new ballast, and new timer under warranty, all of which I have had to fit myself. The skimmer doesn't seem entirely right either - it deposits waste on to the inside of the skimmer body (I've checked the intake pipe is clear), below the removable cup. Add that to the cheap cabinet, and in retrospect I wonder whether I might have been better off with something else - in fact it is only the difficulty of establishing a new tank and shifting my existing corals that stops me going to something else.
To their credit, the local distributor has supplied replacement parts and offered to pay for an electrician to fit them, but it certainly has not been 'Plug and Play' like the sticker says on the box - in fact I doubt its been any less hassle than builting your own set-up from scratch. Those issues notwithstanding, it has allowed me to get into marine, and maybe allowed me to avoid other problems to do with compatibility along the way. I just wish the build and component quality had been better.