Paul, you realize that with your local LEOs running lidar, neither detector is gonna do squat for you. Well, it'll go off to let you know when you should pull over for the LEO that just tagged you doing 15-over. Realistically, lidar is "instant-on," meaning there won't be enough time to detect it and slow down in time to not register as speeding.
If you want to try something that'll actually give you a chance against lidar, then you'll have to look into a laser jammer. No one seems to know which one is the best (or, at least I've never had anyone give me any useful information when I've asked this question on this board a couple times in the past), but I've heard good things about the Lidatek system. It runs about $600+, IIRC. But it will actually jam the lidar gun for about 5 seconds, giving you a chance to slow down.
FWIW, I've got a V1. But I realize that it's pretty much worthless against the state troopers, who mostly run lidar from the side of the highways here in Mass. It's still good against troopers in cruisers (lidar can only be used from a stationary LEO), and most local police (as lidar doesn't seem to be used by them, yet). Don't know if I'd trust much of what's available in the $150 price range.
edit: This link may have been posted in the past. Remember that while some science is used, this site is also trying to sell products.
http://www.radarbusters.com/support/speedlabs-2006/default.asp