Ok, boring f#$k that I am, I finally found 5minutes to sit down and work out the difference between new and old profit share.
Until profit is over 11.5% of turnover, new scheme is better. Old scheme(25% of profit in excess of 7.5% of turnover) is better until 22% of turnover. At 16.67% the difference is greatest at around 10% profit share...ie if we got 60days on new scheme we would have got 66days on old scheme.
So to summarise, new scheme is better up t0 11.5% and then again if profit is excess of 22%. Old scheme is better between 11.5% - 22%.
Out of interest, since 1994, profit margin has ranged from -2.1% to 14.5%. Only in 3 years, 1996 2000 2002 has profit margin exceeded 10%.
So whilst the current profit share seems parsimonious, it is in excess of what we could historically expect to receive from this employer!