Thinking about a scrubber . . .

I have a very nice Flex 3401 that I'm mastering (gifted to me by a very kind older brother who may or may not have known that he was starting me down the path of spending hundreds . . . nay thousands . . . of dollars at Autogeek).

I'm thinking I'd like to add another machine for use as a scrubber for shower tile, carpet, polishing aluminum door sills, and maybe even some sanding (although I'm not much of a woodworker).

The Dewalt 849X and the Porter Cable 7424 both have appeal, as they both seem to have a decent assortment of brushes and backing plates to do nearly anything I need.

I've thought about just using my Flex, but I've been unable to find much in the way of accessories and various sized backing pads, which is why I'm looking further.

The cost difference isn't a factor, and I'm not likely to ever try to use the rotary on my vehicles, so there's no particular value in adding a non-orbital like the Dewalt to my detailing arsenal for that.

I guess it really comes down to which one would be the most effective as a scrubber, would have the most versatility in terms of backing plates, and would generally be a better machine for that purpose.

And, of course, I'm open to other suggestions of any kind--I'm not experienced enough yet to really be able to think outside the box. I only want to avoid cheap tools because I learned long ago that I end up hating a cheap tool every time I pick it up (I'm fine with inexpensive, though!)

I hope that's not too much of a ramble, and I appreciate any thoughts.