It's hard to move it around especially if you are using canopy or if your tank has a wide lip.
Moreover, Cord length will be annoying, you need very long cord when you are cleaning the bottom, and you will end up with free flowing tangle everything cord when you work the magnets to the top.
I use both a Pirahna float and a Kent Pro Scraper for the difficult stuff. The Pro Scraper is wonderful on coralline ... and good for `perfectly clean' every month or two when I have a lot of guests.
The Pirahna is great for the once/twice a week I have to swipe the glass. One pass, it's clean
Both are good tools. My old MagFloat is in my softie tank, but I never was super happy with it's relatively weak magnet [IMO] and found the Pirahna to be not as thick [more clearance in-tank w/ rockwork] ... just barely, but combined with working better IMO - worth consideration.
[best of all, I got mine used ... as they sell replacement pads it doesn't really matter]