Yes, I do like the Mercury browser, I have it running with the Chrome user agent so now I can have WYSIWYG post editing!
One problem though: it doesn't seem to want to play embedded YouTube videos whereas Safari does. It could be that the user agent is involved in that, if the embedded video is being served as Flash unless an Apple device is detected. Also, touch screen support is not so good on the non-mobile versions of sites, even if some of the functionality is not available on the mobile versions! What it needs is dynamic user agent switching.
I have suggested posts 65, 66, 68, and now 69 are broken off into an 'Arms topic "Alternative browsers for iOS", but nothing seems to have happened yet.