400 doesn’t have manual ground balance,which will false more and probably not as deep as the at pro for that reason.
I’d skip th at max if you don’t hunt at night,imo I’d get the at pro..Even used they’re steal right now..No matter what machine you get your gonna find cool stuff,so I wouldn’t let too much influence you on your decision..Just look at what features you most want in a metal detector and let that be the deciding factor.
I’m currently using a bounty hunter - treasure hunter 2... it was a cabelas edition. My dad has the at pro and I love it, he thinks I should just get the ace 400 though, he’s probably just thinking about price since I’m not the richest guy on the street lol
Pro is a very decent machine. the 400 is not. The 400 is youth designed with the short cuff and very heavy standard coil (nose heavy). The 400 has fixed ground balance which limits it use in some soils, requiring the sensitivity to be set very low thus loosing depth. Go with the pro.
I started with the AT Pro. Very good machine for coin shooting. I ended up putting the 5" x 8" Garrett coil on the machine. Very nice to swing and good finds ratio. I now use a Nox 600 but the AT Pro is my back-up and I do still use it from time to time. I'm sure you'll not go wrong picking the AT Pro.
Bubbaron NOX 600, AT PRO, AT CARROT PIN POINTER
I'm biased, but I would go with the ATP between the 2. I started detecting last year and did quite a bit of research on the ACE series and the AT series. The ATP does cost a bit more than the 400, but in the long run you'll thank yourself. With the ATP you shouldn't have a need to "Upgrade" your machine for some time. The coil options seem really good with the AT series. I use the 5X8 coil 99% of the time and it works well, especially in high trash areas. Good luck on whatever you choose. Garrett customer service is second to none as well...