The Z5 machine is pretty good, but I'd say a few things could be improved for example
1. The body of the machine could be slimmer to make it easier to handle
2. The depth adjustment tends to collect dust due to it's complete circular design
3. The keyless chuck doesn't hold the bits without tightening with a spanner
4. The xbit FT1 just doesn't cut floor tiles
I thought this would be the answer to all tilers prayers but it's not.
No way can it rival the Fein but I got one of these to cut tiles with and it aint all that hot. I can't imagine it coping with porcelain - it would be quicker to set up your wet saw and use that than the time it takes this thing (even with diamond bit) on a floor tile.
I will, however, keep the Rotozip. It came in handy trimming the edge of a tile behind a socket on a kitchen splashback (saved me from removing tile) and is very handy for plunge cutting holes. Not as neat as a core drill but when the hole is going to be covered with a fitting then this tool will save time rather than faffing around with water and drill bits.
To sum up - glad I've got one but wouldn't replace if it got nicked - I wouldn't be without my Fein though.
Nick from Rotozip visited Pitt while I was there and gave us a demo. He used a very different action to what we'd been using and the diamond bit cut the tiles like a dream, was hoping he'd give me a replacement bit as I'd burnt mine out - but no.
None at all, unlike my attempts at using it like a jigsaw. Basically he got it started with a rotating action until the bit plunged through and then start sawing.
I'm just glad I haven't wasted my money, but it looks like the place where we got the rotozip from maybe forced to increase their prices.
I've been having a go with Dave's rotozip and have found it to be pretty good for those plunge cuts. I see the only downfall being the cost of the xbits.