Cant speak for the BPW coaches (unless Ian is one of them), but I did half a day’s training as part of a group (of STW Tuesday Treat winners) with Ian Warby earlier this year at Aston Hill and found it really useful. I’ve definitely changed my riding style since and am riding faster and more in control as a result.
1/2 a day as part of a group was just about enough to get the basics covered and iron out a few small issues, but I think you’d need at least a full day as a group or half day 1-2-1 to get the most benefit, especially if you have some bad habits or are struggling with anything in particular.
I wouldn’t be too put off by the group thing either as he didn’t just stick to teaching the same small bit of technique to all the riders at the same time, as you make progress, the advice was tailored to each rider, so while we were all sessioning the same small section of trail, those who had mastered the basic technique were given more advanced techniques and harder lines to try.
Been meaning to book a 1-2-1 for a while now, but never seem to get round to it.