I've used it often. But since it tends to start drying alomost as soon as you start applying it, it's difficult to prevent leaving brushmarks. One way round that is to thin it, but then you'd probably need two or even more coats to provide proper cover.
No but I've always suspected its effects would be those described by heathfield. However I might be wrong as, being a terrible painter, apart from overloading the brush I do tend to keep on messing with every coat and end up in the same boat as heathfield describes (plus paint runs).
For an indoor matt-finish, I have occasionally used just white undercoat - it goes on to give a perfect finish even in my hands. Don't tell anyone please!
Luv O_G's contribution, lol.
SIQ.
I've used it and love it - by the time I finished two rooms I was able to go back and put the next coat on. Having said that, I'm not fussy about brush marks.... I didn't notice them but no doubt I will now!
I always use it, having four legged furries running about who won't be told to mind the wet paint it's essential in this house. I don't have a problem with brush marks and as Misky says it's so much quicker to get a second coat on and get the job finished.
The only water-based 'top coat' I've used where you can get a decent finish is Farrow & Ball acrylic satin. It's expensive, but well worth the extra cost.