Tl Dr version: this is a good cage once it's up, just keep in mind it's budget. Anyway ...
... You probably see £235 and think "this must be an amazing cage". Let's be clear, 235 for a full steel cage as big as this (it's just over 5ft including the legs) is cheap. Quality cages of this nature begin at 500 quid. With that in mind the bad aspects first: it's a pain up the backside to build. Think of it as being like a double bed for a couple of hundred from The Range vs one for £750 from a specialist dealer. Yeah it looks the same, but it's not precision made. Everything from the welding of the bars to the frame to the positioning of the screw holes is adequate for the task, not precision engineered. The instructions are one side of A4, including a few lines with such detailed directions as "assemble the bottom half, attaching the front and back panels to the sides with screws". As for the instructional video on the page, I don't know what cage they're putting together there but it isn't this one. This one will not go together as smoothly and easily as that cage which i suspect to be a proper high end one purchased specifically for the video. I had to work out how to put this together as i went, bullying and bodging bits into place along the way. It took 3 hours and I strongly recommend getting someone (preferably a tall someone) to help you. The trays that go in as the flooring are also so floppy they might as well be plastic. That said, the good aspects of it ...
... once finally set up, although clearly cheap, it's pretty solid and obviously enormous. There's loads of room inside. It's as wide as a typical large one tier cage and about 5ft 2 on its stand. Although it's quite awkward to get stuff in there because only one side is actually a door, there's plenty of room to put hammocks, climbing frames, ladders, ropes and, of course, at least 3 rats. I'd say that it can probably accommodate 5. Cleaning is also a doddle since, although floppy, the trays slide and lift out very easily l and their coated metal construction makes cleaning them a simple matter of spraying and wiping down. Plus the fact that it's on a set of pretty sturdy wheels makes it very easy to wheel around should you decide to relocate it.
Overall it's OK. If you have at least half a grand to spare go looking elsewhere for identical looking cages of a higher build quality. If you can't stretch that far, as many can't, and you have the patience to devote 3 hours to bodging it together without instructions, then this isn't actually a bad option. Just remember to manage your expectations and inspect every piece before assembly.
