I usually like any episode where Jack gets to show off his military skills. <G> But that's not the only reason I liked Touchstone.
Besides giving us the episode arc that led to Shades of Grey it also gave helped to eventually give us a lead in to WaterGate and followed up with what happened in Solitudes. It's one of the reasons I find the show so fascinating at times. They'll take these little things and eventually make something of them.
It also brought out how we have to consider what our actions are going to do with the other societies that we encounter. We can't just go in and take without knowing what the consequences of our actions are going to be.
It also set up the premise that we are somehow 'our brother's keeper' in that the SGC has to keep an eye on what others are doing with what they are finding on other worlds.
The Woolfden: http://www.woolfden.net