Duratex is easy to roll on, but hard to get a perfectly streak free surface. It takes some practice to get there. I've done a few jobs with the stuff (audio and non-audio). It is a very forgiving coating, slight imperfections and whatever end up on the paint job, not noticed.
I was very happy with my last sub Duratex paint job:
Everyone has their own formula for painting the stuff, there are older threads on this subject. Here's mine (cut and pasted from notes). I use the yellow foam rollers from Home Depot:
http://www.homedepot.com/p/FoamPRO-9-9-in-x-3-8-in-Smooth-and-Semi-Smooth-Coater-Foam-Roller-Cover-156428/205037233
1. Paint/roll on two coats of 50/50 mixture of Titebond II and water, as MDF sealer.
2. Let dry, then lightly sand out air bubbles from glue mixture.
3. Paint/roll on two of water based gray primer, to show any surface imperfections.
4. Let dry then sand to smooth, remove any dust.
5. Lay down a heavy coat of Duratex (as in barely “too much”), with roller, spread around evenly.
6. Unload extra paint on roller onto spare cardboard pieces.
7. Hit curved corners at a 45 degree angle.
8. Then lightly, with NO pressure, go over main area with roller, in one direction only, with many tight overlaps, until there are no streaks.
9. Wait 15+ minutes, and then go over with dry, un-coated roller, also with NO pressure downward. Do not allow Duratex to tack up on dry roller. Exception: Do not dry roll after last coat of Duratex.
10. Let dry for a minimum of 60-75 minutes before recoating.
11. Sand down with 3M “Between Coats” finishing pads in between coats of Duratex.
12. Use 120 grit sandpaper on heavy spots (runs, etc.).
13. Do a minimum of three coats per side, keep roller in baggie, and sealed up when not using.
14. Duratex needs a minimum of 7 days to be totally cured.