Edited for clarification. IF I have to pick pro or con on the mod issue I guess for the deck I am con. This in no way reflects on Chris, since he is the only person doing mods right now. In fact I have owned a UA-5 modded by Chris and a pair of LDC mics that he worked on too. With that said......
Kirkd
The mod Busman offers is only a "Transparent" mod. I posted his description of what he does earlier in this thread I believe. All he's doing is adding better quality parts that result in less noise and better soundstage.
I was working as part of the crew with Chris at the Bluegrass gig he cited. We had time to talk about the stock VS mod unit.
Better quality that results in less noise. For nature or maybe dialog Sure why not. But for me, I record live amplified music 99.97% of the time. There will be more noise from the crowd just talking than there will ever be from the recorder. And I think for most applications this holds true...that the "noise" of the "room" or location will be above the units stock noise floor and or the mics noise floor. It becomes a moot point. A better soundstage.....I guess if you are recording as a stereo pair. I almost exclusively use the deck as a multitrack unit with mono channels and "placement" of the sound is accomplished in post when I mix. For me, the $300 is better spent else where. Like I said it comes down to personal choice. To each their own. IF it works for you then it is right for you. Having the $300 works for me so it's right for me
I'd also look at it this way....If the Preamps are nearly identical to the specs of the Sound Devices 7xx series recorders, which many consider to be the "industry standard" why change things? Granted the two units are not built the same, the &xx are built like tanks. If you had a 744 or a 788 would you want to mod it? And like I said before WHAT IF you did not like the way it changed the sound, then what? IE: what if you thought it made the mids to bright, or you perceived more of a harshness after the mod or pick anything but WHAT IF you didn't like how it changed things? I would NEVER go back to someone like Chris and ask him to undo his work, I think it would come off as an insult, so then what would my options be, send it to Tascam and pay full charge for factory work since there is no warranty now? I could go on, but I think you get my drift. It really comes down to that dreaded personal taste...it depends on what you want for your unit. For me I'll stick with stock and spend the money on more toys