I have both, the Plat Pro and the AT. The Plat Pro is no slacker, I paid $400 but contact a sponsor here and they will give you a much better deal and super fast shipping.
About the BH, I wish I would have just went with the reg BH Plat and not the Plat Pro...reason being: with the reg Plat, it is the very same detector but with the smaller coil for about $100 less. I wanted the larger coil, but should have just bought the reg Plat with the smaller coil and then....I could have bought the larger coil (about $110) and had 2 coils, or sell the smaller one and get some funds back to put toward the larger coil. Either way, same detector and larger coil for cheaper. I hope that makes sense.
Pros and cons of Plat vs AT:
Weight (huge factor for me): easily goes to the BH. Light as a feather at 2lbs. The AT is pushing 3lbs, but neither have slowed me down once you get used to swinging. I prefer the BH just because shaft design.
Toughness: I have beat the hell out of the BH being my first detector. It is pretty plasic and delicate, but you don't have to be delicate with it. AT Pro is plastic and delicate as well, but you do have to be delicate with it. Control box is wonky and top heavy, likes to try and fall sideways when set down to dig.
Warranty: BH is 5 years strong, Garrett is 2 years but they have awesome service and do their customers right well after warranty period.
Performance: BH is a true ground balance and go detector, but only 3 bell tones which gives limited info on targets but very very fast reaction time even when bouncing off tricky targets like bottle caps. AT Pro, hands down is the winner here. Can do everything the BH can at only half the capacity, the other half enables Pro mode which is where the AT Pro completely destroys the BH. No comparasion. Huge amount of information given about targets, which can be frustrating at first until you learn this detector but once you do, then you are extremely thankful!
Water/weather proof: if it spinkles even slightly, you won't be hunting with the BH. This was also a huge factor for me. Sometimes during cloudless sunny days, we'll get a complete random sudden 5 minute shower. Doesn't stop the AT Pro, you can take it under 10ft deep without issue.
Customizations: You can make the AT Pro all yours, many things can be done to make it stronger/stiffer/tailored to you. But, much like owning an Iphone, you have to get past Garrett's adapters to open up some options. They have unique and special connectors that cost a few $ to get past. The BH, no customization available. It is what it is, other than changing coils.
I still use both, mostly the BH when I'm dinking around and only lightly/moderately hunting. Easy in and out around metal equipment, and never get tired of swinging it. Some people compare this detector to a toy, and while not super advanced...it is fun to swing and has never done me wrong. Still over 4 years warranty left! In 6 months my coin finds with the BH, bought me the AT Pro.
When I want to hunt and hunt hard, no doubt I grab the Pro. In the wide open, it is a killer. I'm still learning it and have quite a way to go. Can be manipulated digitally to hunt harder/more precise.
The BH is an easy detector to learn, after 6 months I became a little bored with it because while very good...it was my only option at the time. Got the AT Pro, and can tell this detector can keep me interested and learning for about 2 years. I'm not even halfway near knowing exactly what this detector is trying to tell me or how to fully take advantage of manipulating it for my best hunting needs. It is a moderately advanced detector and being waterproof opens up even more options/territory.
I hope this helps you. If any questions, feel free to ask!
