I know many have had their issues with canister filters. I currently have 10 tanks in my home, including a 180g, 125g, 75g and 65g tanks. I have sump filters, Fluval FX filters, Fluval 30x and Fluval 40x filters, aqua clears, and ACO sponges. FX filters were definitely purchased at PetSmart's half off sales (as @Randysaid, amazing deals or even steals!)
My original FX6 had a leak at the pump due to a failing O-ring. Thankfully, I caught the leak in time before any serious damage. However, the leak only occurred after a year or so of use, and I must admit that I performed little maintenance on it. I am committed now to opening the canisters in intervals of less than a year. If not already depicted, these guys are champs.
Yes, maintenance is not easy. Yes, I have to always pull up the instruction manual out on the FXs (not the 30x or 40x) to make certain I am draining, filling them up correctly. But that is a testament to how rare how I actually perform maintenance on them.
I am not a Fluval salesman. Would actually love to put sump filters and sponges on all of my tanks. But right now, the canisters are working just well, coupled with aqua clears and sponges on the same tanks.