I bought this tile cutter because I had thought it would be faster than a manually operated one, but it didn't end up being faster at all. In fact I sometimes lost my temper with it.
First of all, its noisy... very VERY noisy. The sound of it fills the whole house and you will probably want to wear ear defenders when using it.
It has a water reservoir to cool the tile and prevent it from shattering with the heat and friction. In practice, the water that spills all over the tile is incredibly messy and washes away any lines you have drawn on there for guidance.
You'll also want to wear safety goggles as the blade guard doesn't stop water or tile bits from flying towards your face.
The guide fence isn't really that great and you end up relying more on your judgement for doing your cuts.
In my opinion, for straight cuts you should stick with a manual cutter.
If you need to cut a cornered shape out of the tile, this will make your life easier than tile nips, but be aware of the noise and mess you're going to get.
Cleaning the tool is very simple, but be advised: don't clean it in your kitchen sink. The water in the reservoir is full of tile clay and it might clog up your drains.