Excellent feedback thanks gentlemen. Apologies for the long posts but I like to think long and hard when, and how, I spend money like that asked for mid-high range metal detectors today.
I think that $1000 base price saving is a huge bargain indeed and makes the 4500 a very attractive choice.
I do agree that currently I'm in the recreational camp, since I make it out there once every few weeks, though that would increase dramatically to being a weekend hobby when I am finally staring at a sold sign out here. A 4500 would make more sense then as it would spend less time gathering dust between outings, but otherwise it would put an end to the what if's I get every time I take in the scenery out there.
I think most gold in and around Enfield NP was at a bit of depth so that may lean towards the 4500, the SDC2300 would still be useful to clean up surface junk so buying one of those would open things up a bit for heavy hitting with the deeper units IMO. I've no doubt though that either option would find gold if I, and any other in the same "which detector" conundrum, walk over it and pay attention to what the coil is saying from experiences of other people elsewhere online.
Right now I think the saving on the GPX4500, besides being a known good product with a bit of a learning curve, is almost too good to pass on and something that seems to sell itself to me in light of your posts on generally the same geology as I intend to try my luck upon. I keep mentioning the learning curve as it has loads of settings and combinations compared to the 2300; however given other people besides yourself may still be using it now I may have an easier time learning how to use it than people did back in 2008 (according to an article re-posted on another forum) when it originally was released.
The worst that could happen to me is buying the 4500; using it for a short while and reselling it with the introductory price drop absorbing most of the drop in value as being a second hand unit. The training session would ensure my basic knowledge of geology in relation to gold is up to scratch so it would be of benefit were I to grab a sdc 2300 later.
Best case; I learn the hard way and am better experienced when the next game changer comes along, whilst the next best thing to first division lotto is finding enough color to grab a 2300 and clean up any scraps missed by the 4500 plus for use by relatives (with that important permit of course) keen on seeing what all the fuss is about were I to achieve such a feat.
In short; I'm leaning on the 4500 and think it might be worth the while of others in the same boat, pending location and duration of use.
Let me know if I missed anything; or have other ideas I may have not covered, before I settle more firmly and part with the hard earned coin.