They're pretty good, actually, especially over slab. The most work you'll do is lifting the machine into your vehicle, and then lifting it back out again. It wouldn't hurt to put a little weight on it, though, while using it. Like a bag (or two) of thinset.

There is no simple yes or no answer. It can be done with the proper preparation and investigation into the condition of the vinyl and how well its bonded to the surface below.
ciciliotandson

Okay. Once again, let me post this, copied and pasted from my website:

This is a subject that's very hotly debated within the industry. It seems every manufacturer has a thinset that they say can be used over resilient flooring (sheet vinyl) or vinyl tile. The problem with that is twofold. With all the different types of vinyl flooring out now, it's tough to know which ones can, and which ones can't be tiled over. Cushioned vinyl's are out. They can compress, causing voids under the tile, ultimately causing failure. Also, not all sheet vinyl is glued solid to the floor. A lot of times, vinyl installers will only glue the edges and spot glue in the center, and if you thinset the tile to it, it won't stay very long. In my opinion, vinyl tiles are out, as well, due to the fact that the thinset bond is only as good as the bond of the surface under it, and I've seen vinyl tiles ( especially peel and stick) let go way too easily. The same is also true for sheet vinyl. The second problem with tiling over vinyl is the underlayments used for vinyl installation. Normally, in woodframe construction, there are one of several underlayments used-- luan, 1/4" particle board, 1/4" plywood, and sometimes even MDF (medium density fiberboard). ANY of those in a tile subfloor is a guaranteed failure. 1/4" plywood has a nasty habit of delaminating (the layers come apart). Luan has the same problem, plus it can compress to 1/2 its original thickness from normal residential foot traffic (I've seen this happen). Particle board (as well as MDF), just from humidity, can expand enough to pop tile loose. Any of those can cause failure, and unless you pull the vinyl, you don't know for sure whether the vinyl installer just went over the existing subfloor, or added one of the underlayments mentioned. All in all, it's an extremely risky installation, and my question is why, when spending the money it costs for a tile installation, would you want to gamble on it?

It's next to impossible to say for sure, without tearing into the vinyl, whether or not it's safe to tile over. Your ONLY recourse is to play the odds, and the odds are against you.

Thanks for the replies. Another question about the floor scraper - does it get up the adhesive as well as the tile? Or, how important is it to get up the adhesive? Again, I appreciate the help.

You won't get up the adhesive. Go right over it using an unmodified thinset mixed with a liquid latex additive full strength. My preferences would be Laticrete's 317 thinset mixed with their 333 additive, or Mapei's Kerabond thinset mixed with their Keralastic Additive.