If I stop more than a week I loose a lot of speed for lead guitar.

I've found out that I don't really loose much technique as chords are concerned. It takes me about 2-3 weeks to get rusted with chords.

But I loose very fast my lead guitar if I don't play once in a while. I try to play a least 15 mintutes of improvised solo each day. I don't improve much with this but at least I don't loose what I have.