Those Golfsmith type mats are fine for a driver and even fairway woods, but I worry about using those relatively thin mats for irons; seems like a good iron swing would want to chew right through the mat, failing that it would be hard on the wrists.
I tried using an old bathroom rug last night; it's now shredded.
The Flextee looks like it would absorb some of the shock (I'm a sucker for infomercials).
Only one range near me uses mats, all the others use real grass, and they look like that were attacked by hordes of giant divot eating locusts. I'll check with my pro and see what he might have for sale.
One thing that's not to bad is a cheap mat lying on a rug. I take practice swings on an astroturf welcome mat lying on berber carpet. The rug absorbs some of the shock and the mat will last pretty long.
I've been thinking about a net as well. Not because of winter but because the nearest range is about 25 miles. If I get one, I'm gonna get one of the bigger mats. Then I'll build box out of 2x4s and fill it with gravel and packed dirt and put the mat on that. That should eliminate excessive wear and broken wrists.