re: interesting ... but ...
<<<secondly, all very well launching phones like this on PAYG but no-one seems to do decent data rates ... Tmobile seems to be £1/day or £2.50/5days if you remember to text a code. If a network came up with a data only monthly tariff with PAYG top-ups for calls texts then I'm sure I'm not the only one who'd sign up.>>>
There are two new TMobile internet boosters that don't seem to have been publicised yet (but are explained in an leaflet with the Pulse) that should satisfy you:
a) monthweb, "one month's worth of internet access " for £5
b) 6monthweb for [hold onta your socks!] £20.
Yep, £3.30 a MONTH.
(Both are activated by text and deducted from your PAYG balance. You can get a reminder when your balance hits a definable value.)
Works for me! :)