Ive always been happy with cormar in fact for the money at cost I think the pricetoquality ratio is quite good, I tend to sell mainly natural berber twist for my private jobs in a 45oz and never had a complaint about quality or a dodgy batch, I also when on the carpet for the firm I work for am usually given cormar to fit (new builds) I aways find its easy to fit and can get a decent tension on it as it stretches for miles so no complaints my end.
Berkley Homes in housing association plots put down generally polyflor colonia on the ground floor with 42oz home counties for the carpet everywhere else so not bad for some immigrant/junkie/chav to have me thinks, they are hardly gonna stick ryalux down as what ever they put down gets f***ed within 6 weeks anyway unless the tenant looks after it (which 75% don't).