moscode 600 " the newest mods"

I have a maxi version 600. I bought it new in the 80's. It's been a very good amp and I still appreciate it's contribution to my system. I notice that George Kaye the original (engineer) designer of the Moscode is now offering some major mods and a rather different approach for his original design. The description and resulting changes to the sound are very alluring. The upgrade package could run into the $1500.00 range. I obviously like George Kaye's ideas on reproduced sound and I'm constantly trying to improve my set up but, it's a lot of bread, so I was hoping some of you may have had some of these modifications carried out and might be able to offer some comment on the results. I would actually appreciate any insight in helping me arrive at a decision.
I would think the mods are probably going to get you a lot better sound. The Moscode amps (I had the 300 myself) are really nice sounding especially for the low low price you can find them used for. As far as your amp being worth 1500 bucks more once you mod it. Mods don't translate to higher resale value that is for sure. If you are going to keep this amp for the rest of your life I'd say go for it but if you are thinking of it holding it's value, maybe not.
George Kaye has been modifying the Moscode 300 and 600 amplifiers for almost 20 years. If you like the rich full bodied sound of your amp you may not like the mod.

I always find it intersting when audiophiles have their equipment modified and shortly after it is for sale.
I have heard several of his mods. And the are better. More detail, quieter, stiffer power supply. You may want to consider buying one of his newer models. You can trade it in or sell it. I owned a 600 with all wonder caps and I loved it. I liked it better than the GK Mod. Mine was stock with all Wondercaps. We compared 3 600 mods and the wondercap mod unit was superb compared to the other two. I don't have any idea why but it was excellent. If you have planars or electrostatics this amp is hard to beat. I agree with Rrog and Ejlif. Many of us have items modified then sell it shortly thereafter and if you are not careful the mods vs resale oo not translate into added value. Many times you lose funds on the mods. A already modded Kay 600 sells for under $1,000 on these pages most of the time. Some more some less. It depends on the times I guess.
I tend to agree that it's not a cost effective move in terms of resale, but the alternative (using it as a trade against Moscode's newest amp will run into a few grand $$$$ and I'm just not able to spend that much. Recordho's point that the wondercap upgrade was very worthwhile helps me picture what I might be getting for the price of the mod as George also upgrades all the caps in one of new mod packages. I also realise that the 2 big power caps are getting old and may have to be replaced in the near future, that would also be done in Kaye's full-out mod package in fact he steps the caps up tp 55000mfd (if he can get them) or at the very least he provides and installs new 25000's. I thank all of you for your input.
I still hope to hear from some folks that have actually had some of these most recent mods carried out by Kaye.

Most people responding to my thread seem to equate the Moscode as being ideal with planars or electrostatics. I have used this amp together with my dynamic accoustically suspended 80 series (pre matrix) B&W 802's aided by Cardas point to point internal soldered connections (sand box isolation damping) and Townshend super tweeters. they sound fine to me and celebrate every improvement I make upstream.