The old mountain master was a great shoe. The only approach shoe I could do a full day rock climb in - approach, climb, glissade, hike out. The Guide Tennie is lighter, but flimsier - I don't like it on snow at all, although it's great for stuff like Squamish. Probably because I don't use them as much because of this, my current pair has lasted three years.
I've also had La Sportiva Boulder X's for the last couple years. Sadly, they are durable but they also suck. Pieces fall off the sole, laces break, rubber isn't very sticky, toe hurts when walking downhill. Finally wore through the rands last week.
Got a pair of Camp 4's on order. These look like a really good one.