In reply to Mountain Spirit:
Sounds like you had a great coaching experience.
For what it's worth, I often think of sport climbs (my main area of experience) by the difficulty of boulder grade in their crux.
I think if you can boulder V3, you can do the crux on a F7a, or on a pumpy F7a+ (i.e. this will have quite a lot of V3 moves).
If you can boulder V4, you can do the crux on a lot of F7bs.
This just comes from my experience - until recently I'd not bouldered consistently harder than V3 but nevertheless ticked quite a lot of F7as.
For trad it feels to me that onsighting V2-V3 (outdoors) feels about English 6a.