I can't comment on the Platinum, but I have owned a Discovery 3300 since they first came out. It IS a slower swing machine, but when coupled with the 4" coil is DEADLY in high-trash areas like tot lots, concession stand areas at high schools, under bleachers, etc. I've picked a mountain of clad out of areas like these, but it takes extreme patience to swing the coil slowly and thread in between all of the trash. Haven't found any rings other than when folks would call me find one that they've lost, so the 3300 will find the jewelry, but it's just not in the areas I hunt. It's a good overall machine, but my instincts tell me that the Platinum would be a trade up. I'd take a strong look at the Omega 8000. That's one I'm considering on my upgrade short list. Easy to use knobs, some notch capability, not too much programming to fool with...but to each his own. Given that you can get the Platinum at some online retailers for $299, it's hard to beat.