In addition to points above re using Avios for long haul / premium cabin travel - the only other value I have found (with help from some of the posters here!) in short haul redemptions is for family holiday flights.
Normally I would pay for a few bags etc. and fares for peak periods are quite a bit higher - while Avios availability seems to be pretty good. If you call EI after booking they will also allocate decent seats.
We have a European trip booked later this year for 5 people and I think I have saved about €900 and spent 67.5k Avios
(1 of the 10 legs booked was a cash booking as only 4 Avios seats available)