I've got a ducted fan sport model called a Renegade. I've always landed it with flaps down, but at first it only had around 25 or 30 degrees throw on them. I had a lot of trouble with overshooting the runway, as the plane's slick and relatively heavy (though not so heavy for a jet). With closer to 45 degrees flap my problem was essentially solved; now I can make a steeper final and, if it's coming up short, just bump the throttle up until it gets where I want it.

I don't think that the flaps slow the stall speed very noticeably; in fact possibly the reverse. For myself, I'd rather have a plane that can make a steep descent rather than fly very slowly. The steep descent means that you don't have to gauge your airspeed or altitude as accurately when you turn onto final, and so you can play it safe by keeping it well above stall speed.

That plane sold me on the usefulness of flaps for relatively low drag models, and in particular on the value of real, separate flaps with large throws as opposed to flaperons which usually have much less throw.