Hi
Randy (and the rest of ya !

).
I'll e-mail you more of my thoughts when I have a mo. to do so, but a few observations for now that for me stand out :-
Ratings : Am I rating them on an objective standard or a subjective one ?!? If its based on what alliances
should give us then I give OW no more than a
C+... but compared to *A they get a
B+ in my book.
Its also hard to rate and compare alliances when the key aspect - the flying experience - is on individual carriers, not the alliance.
So I'm not sure I can give ratings either !
This said, the headline specifics that make OW my alliance of preference, and that explain my comments above, are as follows. (I will try to keep my comments to alliance issues, not to the merits of OW airlines/carriers over *A/SkyTeam ones, but will mention individual carriers when it relates to alliance benefit delivery [e.g. quality of lounges]). Easiest/best method is via a comparison :-
OW v *A etc
Day of Travel Status Benefits/Recognition - For me, as a very frequent flyer who is often down the back, this is by far the most important consideration - I emphasise
'Day of Travel Status Benefits' because to me these are
FAR more important than the clear benefits of many *A carriers over OW ones, namely super-generous mile bonuses and redemption rates etc.
Lots of miles and free flights are great of course, and will matter to me when I'm retired, but my key concern now is receiving as easy, quick, and relaxed a travel experience as is possible when travelling, and travelling so much. OW win hands-down in this regard over *A.
Key examples :-
Check-in - As OW Emerald I get to check-in at F desk even when in Y. This saves me at least an hour at LHR T4 for e.g. over the Y queue (the poor people in the queue in that absurd system

), and on a busy day 15-25 mins. over the J queue. On *A (as a G) I join (at many airports) about 60% of the pax who are in a long line for the J check-in !
Lounges - F lounge access even when in Y. And generally to excellent lounges with real facilities and real food etc like the vast majority of BA, QF, CX etc lounges. CX HKG lounges are the best that exist, BA ones at LHR (in my home town) with the MB Spa etc are fab., etc, etc, etc.
And access to Arrival Lounges (where available of course) even when flying in Y. Great benefit. ^
This is in comparison to total non-access to F lounges on *A unless flying in F, and the disgrace that are many/most *A lounges (including some of the F ones). So many of the *A G lounges are truly awful facilities by comparison (and so often are full to the brim).
On OW I can (before flying in Y) have a bath in the lounge (CX HKG) or a massage (BA in LON)... while on *A all too often there are not even showers available for me to use.
General - *A wins over OW hands-down a) on op. upgrade rates (*A carriers are way better in my experience in this regard than OW carriers (apart from the exception of AA for its own FFs) - QF for e.g. almost never OpUp, rare too on BA); b) no. of seats made available for upgrade and award redemption; and c) with the new Alliance-Wide Upgrades idea.
Otherwise its OW for me all the way - they could and should give their top tier FFs a lot lot more, as should the individual carriers that constitute it, but are very clear winners for me in a head-to-head with *A - cos, bottom-line, when I fly across OW its a vastly better, easier and more comfortable (even luxurious) experience than when I fly across the *A network, almost every time.
SkyTeam (
for me) may as well not exist - not enough airlines/too limited route coverage, airlines I can never see myself picking over OW and *A alternatives (some of which have the worst reputations of any major airline - i.e. AF !), bad status recognition (only very top tier get lounge access), etc, etc, etc, etc.
Oh, and one other huge reason why many may want to choose OW over *A - *A airlines gift status, many absurdly easily, on OW you need to earn it. So if you want status in both but won't be flying enough, earn it in OW and then get it matched in *A. The likes of BD will even match OW Sapph. (as long as its in a prog. that calls it Gold or Platinum

- i.e. QF or AA) to *A Gold, and will match you year after year after year.
And this btw is one of reasons why 'elite' FF experience is so much better on OW than *A - less people so less dilution of benefits (and less people in the lounges, at lines for check-in, etc !), and more recognition of you as an 'elite' FF.
I know of someone (retired, and thus he and his wife appreciating any benefits he can get with on now very limited amount of flights) who has Life QF Gold (OW Sapph.) and has used it to get 4 years (so far) of free *A G status, just by going to one *A carrier after another ! Absurd... and actually encourages FFs to fly OW not *A !!!