Good day all,
Mobile Threatnet is not a bad product - Like anything it has its good and bad points.
I was close to getting this myself, but decided to stick with $60 a month for mobile broadband (AT&T 3G Sierra USB) and SwiftWX ($15 per month) for data, which incorporates GPS, and I did well with that. The "data holes" in Kansas last year (to me) were few and far between.
The point here is USE what works best for YOU.
I found GR Level X to also be great as well, which also works with a mobile broadband connection, and a one time fee.
WX Works is (to me) EXTREMELY overpriced. After the initial $900, it's at least $100 a month (on the chaser friendly plan) and then, to turn it off (and on) you are slapped with huge fees. Now, ofcourse, this is satellite data, which is never cheap (cruise ships charge $10 a minute for a phone call on satcom)!
The advantage is that you have continuous data, as long as you are in clear view of the satellite - Sometimes I've seen signal drop under trees, and even heavy cloud cover (while a cell / 3G signal is still present).
Also, the radar shading is like the old VIP level 6 display, with the pink shade applied for "maximum DBz" of 55 DBz and above - So if you see a core, and it's only "pink", that does not necessarily mean that its "55 DBz heavy rain" (unless your in FL) until you lose your windows! Make sure you mouse-over the "pink area" to get the SCIT information on it!
Like I said, to me it's a great package, but is rather expensive for someone not a full-time chaser. In comparison, you can turn on and off SwiftWX at a moments notice (on one month, off when not using it - you just don't renew, and there's no fees). GR is a one-time fee with an authorization code. WX Threat Net has lots of fees (I am not a "fee" guy, as you already noticed).