Tom,
I guess it depends on the slant you put on it. For Bristow guys, the pay for 6/6 is the same as they were getting for 7/5, which equates to a pay rise. The Nigeria allowance is not $7,500 per annum - it's been increased by an additional $7,500 per annum ( a 75% additional increase), a rather different thing I think you'll agree. There's an additional incentive for those wishing to work 8/4. I don't think the deal is too bad, but it's a shame they didn't take the opportunity to match CHC on a few other things like the loss of licence insurance or decent in-country medical provision - very important in the present state of Nigeria.
SAS,
The US$500 is over and above regular salary. I don't know if the pension scheme has a 5 year minimum limit. It sounds, as you say, like a 401(k) plan, but may be a bit different if it's set up in the Channel Isles.
I guess it wil come down to people deciding if the extra is really adequate for the extra risks of working in Nigeria for now.