I dunno. Personally, if you are even semi-competent with handling your gear I still think the extended warranty is not economical. I'm figuring the average cost of repairs (both accidental and manufacturer defects) over your lifetime will equal much less than continually paying for an extended warranty. I'd rather take that money and buy another filter, or put it towards that CF tripod and gimbal setup you're hankering for in your other thread
. $250 is a sidekick gimbal, or maybe even an upgrade from Gitzo to RRS tripods.
Insurance is always a good idea, however, especially for guarding against wholesale loss of gear that is difficult/impossible to replace (many serious photogs accrue multiple thousands in gear eventually). I did recently hear some very unfortunate (and very worrying) stories about people adding camera gear to their homeowners insurance, however. When the time came to make a legitimate claim, the insurance company finally paid up and then turned right around and cancelled their policy... their WHOLE policy, home insurance and all. Also heard a story about a guy whose policy was cancelled because the insurance company saw the pics he took and deemed his shooting conditions "too dangerous" (I forget what it was, but it was pretty standard- like motorsports or something).
No experience with Mack Camera and their warranties, but a very careful and thorough read-through of their terms is required before laying down any money. Don't trust a word the salesman tells you- no matter how nice or competent he seems, there's no guarantee he hasn't read the terms himself and may be making bogus claims about them. This happens all the time in big box electronics stores. The only way to verify is to check yourself.