As far as I know Peter the image has an Adobe RGB profile and 23hq don't do anything with images other than store them and allow them to be viewed.
Allan makes a good point. If your not using a calibrated monitor for Adobe RGB it's rather difficult to be sure what colours and contrast other people will see. The same applies to sRGB as well. I was utterly amazed by the difference once I had calibrated my monitor.
As to a bigger gamut I had the impression from Adobe RGB monitors that it used 10 bits per colour channel but it seems that it actually uses 8 just like sRGB but has bigger steps for want of a better word in order to cover the wider gamut. It misses some shades of colour because of that. There is plenty of information about on the subject.
If I print - very infrequently - I use sRGB. There are people on here that even use colour profiles to suit the paper that the print will be finishing up on and use Adobe RGB. Some even have experience of using ProPhoto even though the full gamut can't be seen on an Adobe RGB monitor. Certain printers cover that range as well. There is a decent video on the various colour gamuts here
http://digitaldog.net/files/ColorGamut.mov
This might be view as a sample and pay for any more. Not sure.
Sharpening - there are a number of tutorial linked to from the CinC home page but you may need to search for it off the tutorial page. I think you will find it covers avoiding this problem.
Software - I run Linux so everything I use is open source. To avoid the sharpening problem I would use an application called Rawtherapee for that. The tonal range that is sharpened can be restricted - in fact it wont sharpen hard white and has a halo control option as well.
John
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