The Defaqto star ratings system has been called into question by industry experts following publication of its 2013 income protection (IP) products ranking.
The five-star system showed a cluster of most mutual IP products falling into the three and four star categories with the exception of LV=, Nationwide, Skipton Building Society and the Co-operative, that featured in the five-star band.
Kevin Carr, chief executive of the Protection Review, said: "The most important aspect of an IP policy, arguably more important than the price itself, is the definition of being unable to work, i.e. own occupation cover.
"Some of the providers offering own occupation cover to the widest range of people seem to be receiving three or four stars because premiums might increase with age."
He added it was "an interesting debate" as product price was effectively being placed above quality of cover and suitability.
Ben Heffer, insight analyst of life and protection at Defaqto, said: "We are confident in what we have done currently but we are always reviewing the ratings and we are not closed to feedback.
"But these ratings are based on comprehensiveness regarding the amount of features and benefits the products offer."
Heffer added that the ratings did not point to suitability and Defaqto always recommended seeking financial advice, especially when looking at long-term income protection policies.
PG Mutual's income protection plan received a two-star rating; the mutual said products may be rated on whole-of-market appeal while PG Mutual focused on specialist areas.
David Zerny, marketing manager at PG Mutual, said: "Own occupation is important to the specific professions we look after and so our products could be seen as restrictive in that way.
"It would be interesting to see how Defaqto is rating this system and perhaps less limited features and price may well be what products are ranked on. I would like to think it was focused on what meets customer needs."
Gareth Evans, head of corporate affairs at Royal London Group, said Holloway products had typically low terms assured and were aimed at income groups that would find the full income protection products - as per those in the five-star category - too expensive.
He added there was comfort in the fact that a handful of the major mutual players had made it into the five-star category.
Mutuals dominated the one, two and three-star ranking categories, including; British Friendly, Exeter Family Friendly, Holloway Friendly, Cirencester Friendly, PG Mutual, DG Mutual and Foresters Life.
The five star-band featured; Aviva, Ageas, Connells, Friends Life, Legal and General, Nationwide, LV=, PruProtect, Nationwide, Skipton Building Society and The Co-operative.
Paul Hudson, chief executive of Cirencester, for which its Income Assured Plus plan received three Defaqto stars, said some providers "undoubtedly" added more features but it was not necessarily a marker of suitability.
He said: "You can add lots of bells and whistles and get a higher rating but affordability, good value for money and a better and speedier payment history, for example, are more important."
