It is interesting that you should say that. I had a similar conversation with autovaux recently. when I asked for genuine gaskets he said he had some that were made in the same factory as GM ect.. ect.. I then said I had heard that after market gaskets are prone to leakage, and he replied " we used to have a problem with complaints about inferior gaskets but since we have sourced these from Elring who make gaskets for GM we havent had any problems" A set of cam cover gaskets duly arrived in a bag marked 'Elring' but I was a bit disconcerted when I realised that there were 2 pairs of gaskets moulded together and I would have to seperate them with a stanley knife. They looked more like they had come out of a lucky bag than a factory that makes genecticaly modified gaskets.
That's vectra gaskets mate 
Nope, thats Elring non gen gaskets!
The vectra ones have a much wider base.
yes they have a much wider base and they dont have a solid half moon bit, and I know because I have fitted vectra cam covers to my 2.5
big mistake you will eventually blow your rear crank seal thus expelling oil over the clutch and causing you £££ thats what happens to all v6 vectras eventually
so vectra gaskets wont fit a 3.0 then ah well ill ebay my'n
No fear of oil being deposited on my clutch, its an auto

As long as breathers are kept clear, theres no problem with vectra covers ,unlike crap plastic omega covers they do provide an efficient oil seal. Ive had mine on for 18,000 miles now with no problems.
Although I have heard of this argument about blowing seals ect. and
I have been pondering how to incorperate some sort of pressure relief valve into the oil filler cap which ejects excess crankcase pressure into the plenum instead of blowing gaskets.
If you have any vectra covers give me first refusal
