You really have to bear in mind that this product is Economy PLUS and not Business MINUS. So the majority of the product is going to be a step up and not a step down!
Issues such as a dirty seat, non functioning tray, grump crew are a facet of any flight on any airline though I admit BA has more of it's fair share of grumpy / non customer centric crew. Sadly - not even limited to SH / LH but for mixed fleet crew too (where they have had less time to have become disillusioned with the work or BA.)
I only now fly PE from the UK to Toronto for the space and a small cabin. (not sure how well I'll fair in a 48 seat WTP on a refurbed 777!!) The space, peace and quiet, and larger screen are all worth it for me.
What drives me MAD with BA WTP is some of the inconsistencies such as (warm) prosecco from London but not TO London. (I've had every excuse from cost, not loaded, canadian customs rules and too hard to chill. (incorrect in that the bottles are carried from a biz cart before take off) I have pointed out that chilling biz and first class champagne and customs challenges are overcome on the same slight and so it's a case of penny pinching. (two bottles at 5 quid each wholesale)
The main criticism for me is how after a good first meal service it morphs into economy and so I'd rename it to reflect the plus only lasts an hour or so. (I'm sure if they could change the seating config mid flight - they would!)
I haven't flown the QANTAS PE product but my brother who has flown both airlines assures me it's far superior. Even spending 10 quid a PAX on enhancing the drinks ie champagne, the second meal etc would be money well spent! With the move to PE from Biz for business travellers, the recent improvements recognise the brand needed a refresh and tweaking. Sadly (and it's not a complaint) I've yet to experience the new blanket /pillow etc as I've flown biz / first class on my last two trips.
The main reason why WTP is so right, is watching newbie PAX boarding who look at the biz seats jealously, keep walking into PE, think the PE is economy and then have to walk on again to discover the economy seat they're consigned to for the next xx number of hours.
My most relevant reminder of this was spending $4.5k CAD on PE from Toronto to Sydney. Being in the same seat for 16 hours in PE was just manageable - walking back to a densified 777 economy section with 10 across to stretch my legs reminded me of the reasons not to fly economy when you can afford not to.