Well, it looks like you two have covered 2/3 of the options.
So, when I started looking at a place to fly, I looked at Halton, Booker, and Plaistows Farm (Exodus Airsports).
They all looked like great places to learn. However, I've ended up at Exodus Airsports. That was partly because it was the closest (Halton was a 45 minute drive, whereas Exodus was 10 minutes, and a lot less fuel).
I did look very seriously at Booker, but unless I musunderstood, I would have to buy into a syndicate in order to go solo. Whilst I know that the overall cost was probably about the same, I didn't think I could afford to buy into a syndicate at the same time as learning in one go, and it seemed silly to start learning in one place, and then have to leave and learn somewhere else in order to continue learning after needing to go solo.
So, if you are near High Wycombe, then Booker and Halton are good, but if you are near St Albans, then try Exodus.
Good luck learning :-)....IPZ