Calendar: pretty much the same as in WP7.5 - does everything I need it to do.

The email client is excellent. The linked inbox - where you have all your mail accounts aggregated - is very handy.

Browser: IE10, fast, slick, much like the Modern IE in WP8. What with it being the same thing.

Call quality? Just rang Jo. Crystal clear, in both directions (apparently). Better than my 800, and way better than my BlackBerry (although the BB brute-forces the call quality issue by being ear-splittingly loud)

Radio bands? Er, dunno.

>time passes<

I'm on Orange (now EE) 3G, so I use 1800MHz for GSM and 2100MHz for 3G. Coverage in the UK is usually pretty good (http://studio.orange.../coveragechecker/) but I don't have a 4G plan, so can't tell you anything about that.