Modified equipment...

I think it really depends on the gear. A mod on an inexpensive digital piece is different than a mod on a piece of classic gear say an amplifier or pre-amp.

For classic gear, folks are looking for stock, unmodified unless performed by the manufacturer. There are too many uncertainties related to mods. Unless you are doing it for yourself, don't do it and/or expect to get market value when reselling, it WON'T happen.

Jctubes I couldn't agree more with your post. The point is regardless of performance improvements most folks DON'T want a modified component performed by anyone other than the manufacturer. I have a pair of MC-60's that have been extensively modified over the years by a guy that really knew what he was doing and had extensive experience with this product, he owned a pair for 30 years. They are dramatically better than the stock version that is for sure. But a while back when I tried to sell them, when prospective buyers found out they had been modified they weren't interested.

Does this invalidate my decision to mod them in the first place and would I do it again? No and indeed I would for the pleasure derived from the improvements. You certainly hit on all the important points both pro and con.