I ran the nubz out doors at LH until the track blued up then they didn't work so well. I ran the cubics in minnesota last weekend on a loamy wet track with a blue groove front sweeper and they worked great all over. I have a set of grips and I don't like them on any track. I got them when they first came out and they are way too firm much firmer than the cubics.
I'd buy a set of cubics, bow tie mtr's, cf mtr's, switches, and that'd be about it for outdoors.
You never know what tire is going to work so I have at least one set of every truggy tire made.