Yep this is a redemption deal, but the maths is pretty favourable.
HTC Desire S on O2 - 100 mins, 500 texts, 500MB, wifi access.
Contract 24 months at £21.50 per month
9 months free via redemption -£193.50
= £13.44 per month
QC or TCB* cashback -£50
= £11.35 per month
I didn't get the Orange £10 deal, but this one actually better fits me as the inclusive mins and data map better to my usage. Agreed if you're only after the handset, it might not be worth the bother of redemption.
To get the cashback via QC or TCB - click through from their links and then change the "aw1" in the link to "aw2" (otherwise you'll only see a 7 month deal on this phone and tariff). Note TCB is lower rate, but they should match QC if you submit a claim once it has tracked.
I ordered this last night and my phone is on its way for delivery tomorrow, and TCB has tracked. :)