I started out with the Ace 350 and quickly got bored with it and upgraded to the ATpro.
Which wasn't very cost effective. I should have just started out with the ATpro.
If you have permission to upgrade, of the two then get the ATpro.
The ATpro is like having two detectors in one.
You can initially start out using in Standard mode which works very similar to the Ace models.
When you want to go further with your detecting skills and expertise all you have to do is switch it into pro Mode and it's like having a brand new and more advanced metal detector.
First of all the ATpro has two modes, Standard and Pro. Standard mode is very similar to the Ace models so there will be very little you will have to learn operating it in that mode. There is a VDI screen that gives you numbers that coincide with different metals to help you determine going by sound and the numbers what the object is under the coil before you dig. It also has Pro mode which is a little more advanced but not tough to learn but will help you get more depth. There is also Iron Audio which will give a grunt like sound if iron is under the coil, and ground balancing which will get you more depth which the 350 dosen't have. It also works on 15kHz which is better for finding gold the Ace350 works on 8.25 khz.
The waterproof feature is nice even when you are not around lakes or the ocean. I like going to parks when there is drizzle or light rain because there is no one there to bother you and you have the park all to yourself.
My advice to you would be to get the ATpro. The better deal is to order it in the 2 coil "Spring Package" It has the standard 8.5 x11 DD coil and the 5 x8 DD coil for using in areas with a lot of trash items like bottlecaps and pulltabs, nails ect. In the long run it is much, much cheaper to get them as a set then to purchase seperately. Belive me you will find out quickly once you get to parks and other public places how much better the 5x8 works in trashy areas.
I believe Bart at BigBoysHobbies.net has them still. Call him (Phone: 405-206-9010) and tell him you are from the forums. He is a forum sponsor and he will give you a better deal than you can find on the internet. I have dealt with him several times and have found he is a great guy to deal with and talk to. I have found him to be an honest person who is more than happy to answer your questions and give you an honest opinion on what you should get based on your needs and not his profit margin.
Here is the Garrett site that has many helpful videos on the features of the machine and how to operate it in different conditions. I suggest you read up a little on the features so if you have any questions you can get them answered when you call. I wound up watching the videos and read the users manual online just after I ordered mine so when it arrived I was able to take it out right away and have a pretty good idea of what I was doing with it in Pro mode. I pretty much exclusively use Pro mode now because it proforms way better than the basic standard mode that is similar to the Ace models.
Ace 350 Specs:
http://www.garrett.com/hobbysite/hbby_ace_350_key_features.aspx
ATpro Specs:
Garrett AT PRO Key Features
ATpro manual:
http://www.garrett.com/hobbysite/hbby-manuals/1533200_atpro_english.pdf
ATpro How to Videos:
Garrett AT PRO Training, "From the Field" and Tip Videos
