There are several threads on this site dealing with Cornmarket/Woodchester, including a few by me. My wife (ASTI) now has her own PRSA AVC, paid through current a/c and claiming back PAYE & PRSI. The PRSA is going since April '06 and so far, so good.
Having moved from Cornmarket, we're not 'au fait' with current charges, but your setup costs look "good" - they used to be of the order of €832.
There is another charge that is not down to Cornmarket, that is a 1% collection charge levied by the Dept. of Ed. I believe that this is charged for AVCs collected by other depts also. This charge has nothing to do with the provider.
Then there is the 5% charged on each contribution. Finally the Annual Management Fee is applied. The default fund is the Consensus Fund. This used to carry a management fee of 1.75% (this may have been reduced to 1% in the past few months).
This brings your overall deductions to nearly 8% on your annual contribution. If your fund is returning 11%, then your real return is only 3%. In the 10 years before retirement, your fund, unless you stipulate otherwise, will be progressively converted into cash, with a lower, though less risky, return, so your real return is very poor.