EI awards include baggage (I believe you can also have a seat assigned by calling). Its 20KG on Regional and Short-Haul, 23KG on long-haul. I think the UK routes can offer value in the even you want to check-in a bag and/or book at short notice. Availability can be surprisingly good. Booking in advance, hand baggage only, the cash fares tend to work out better.
https://www.avios.com/gb/en_gb/spend/airline-partners