If you go to the Sovereign forum and look down the first or second page you'll see a thread called something like Light Weight GT Pictures. There is info in there on how I made it so light. I've dropped almost a pound and a half over the stock unit, and I'm using a 12x10 coil. Mainly I used a whites tall man carbon fiber lower shaft ($10), a lighter weight gauge aluminum for my upper shaft cut down in length since the Whites tall man rod is very long, a 3 cell lipo battery, a Whites "heavy duty" arm cup (the stock GT arm cup weighs 8.8 ounces!), an aluminum bike end bar for a lighter and much more comfortable grip with rubber cover put on it, got rid of the coil cover and used spray on bed liner, and a few other minor things. The stock lower shaft is fiberglass and heavy, and the upper stock shaft is a real heavy gauge aluminum. Much stronger then you'd ever need, so I went to lighter stuff. My GT now feels as light or lighter than any machine I've ever owned. At least on par with my Whites. About the only thing I've owned that was lighter would of course be a Tesoro.
For the price of the AT Pro below I think $600 that's pretty good for a water proof detector. It's light enough to be used as a land machine, which can't be said about a lot of water units. Sure, they can be used on land but it's not too fun. Looks like that AT Pro might be a very good seller being a dual purpose machine like that, if it gets real good depth on silver on land and decent depth in the water on gold rings. I like the screen. I don't like that it only has 3 or 4 tones. After using my GT I can't handle a machine that doesn't have numerous multi tones. It makes hunting by ear so much more powerful and I only look at the meter to confirm what I think I hear when I want to. The adjustable iron rejection is nice. I love the fact that they give you the option to hear "unprocessed" audio versus just the "beep & dig" type response that I hate on so many machines, including the Explorers I've owned. Up until now the only machines I've owned that really gave in in depth audio details were certain Whites. My GT gives me that kind of finer audio detail, being long and drawn out to show you things about a target, yet it also has much more in the way of tones than a Whites...so thus far it's been the most telling machine audio wise I've ever owned. Where other machines speak with one or two "words" the Sovereign speaks in long sentences to clue you off to target traits. I'll have to listen to the AT and see how well it's audio is in comparison. It's so cheap that I may buy one down the road just for water hunting, though I'm more apt to buy an older Sovereign control box and stick that in a water proof control box. Since I already have coils for my GT I'd only need the box and an older model could probably be had for $50 to $70. All the Sovereigns for the most part get about equal depth, with some saying the GT is a bit deeper. It's a cheap way to build a water machine, and we all know the Excal/Sovereign is king of the beach in terms of handling black sand, salt, water, etc. I'll keep my eye on the AT Pro and decide down the road if I want to add it to my line up of machines.