Hang on, I've not had my two pennyworth yet!
The results of the mod will be a smoother midrange and better high end detail.
Well, I copied that before I saw that Jon already commented on it - I would translate that to mean a flatter midrange frequency response and some high frequency boost - in the case of the first, I doubt whether it's other than effectively flat already, and if you want high frequency boost, do that in post production if necessary and to your own taste.
If the results of the mod are that the recordings I make sound better than they did before, I'll consider my money well spent.
Your money is well spent if you believe that you've got a better device for it. Whether it is or isn't is immaterial. I very much hope you will enjoy it in that way.
Many on this board have purchased mods from others builders who do not tell you much at all about what they are doing, and I find it interesting that they are not subject to the same scrutiny.
I'm not about to bother to dig out examples but I've verged on making myself unpopular with some comments on what I see as the dubious merits - or to be more precise, the unproven merits - of mods before, I think on these boards, and Mr Oade and I once exchanged some sharp words, as I recall it. But at the end of the day, each to his own. Like I said, it's about enjoyment - and perhaps some of the enjoyment lies in the discussion?
And now, back to our scheduled programming...