We used it for a hen weekend and it had everything we needed for 16.
Location is great, approx 15min walk to corn exchange.
Check in and out very easy and hassle free and all communication was quick and helpful when needed.
Accommodation isn't as big / roomy as it appears on the pictures but still a good space - but I think it may feel very cosy for 20 people.
2 bathrooms each with 2 showers (shared), a mirror in majority of bedrooms and extras on the hall. Kitchen was stocked really well and overall we were really happy with our stay.