White's Coinmaster 4000/D Series 2

I've been thinking about getting back into metal detecting, a hobby I used to do all the time as a kid. I was looking around at various ~$300 detectors available today and am still not sure what to get. Then I got to thinking about my old childhood detector that was hanging up in my garage. It's a White's 4000/D Series2, and I got it sometime in the late 1980s used. It had a special rechargable battery pack that stopped working years ago, and the detector has just moved with me over the years.

So on a whim, I searched the web for my model and found the owner's manual. It talked about the battery pack being six AA cell batteries. I'm such an idiot that over the years I never did the math: each AA battery is 1.5V. 1.5V x 6 = 9V!

I just dusted the darned thing off, plugged in a fresh 9V battery, and it powered on!! The speaker doesn't work, but the headphone jack is still functional.

I brought it out into my yard just to see if it would actually pick anything up, and I found one screw from my raised bed garden project and two pieces of 12" rebar along my property line. Not exactly a jackpot, but it proved it still works. I turned up the discrimination and was able to dial out these items, proving the guts of this thing are still doing their job after all these years.

So that brings me to some questions. Does anyone know anything about this era of metal detectors? With the way technology has changed over the past three decades, are the beginner to intermediate models available today actually better than my "classic" model? I've been considering the Garrett Ace 250/350, Bounty Hunter Pioneer 505, or similar. Any thoughts?

BTW, here's the owner's manual I was referring to:

http://media.whiteselectronics.com/...20Manual.pdf