Certainly take the WTP offer. I don't see what the big deal about CW is to be honest, given the price.

To upgrade 3 flights to WTP at that price costs £450. That's the same as upgrading 1 WTP flight to CW.

I'd much rather travel 3 segments in WTP than 1 in CW and 2 in WT.

Ignoring POUG, take current month-in-advance Saturday-night-stay prices for LHR to IAD for example:

If you had £10k to spend on 12 returns, you could either have
12 in WTP @ £787 each (£9444)
or
3 in CW @£1883 each, and 9 in WT at £470 each (£9879)

I'd much rather have the 12 in WTP. Incidentally that's 2160tp vs 1470 with the occasional club world option.