True. However, having lined up a number of times against 3300s inshore crewed - if you want to be competitive in that area you're not going to like the 3300.It is certainly a possibility and with only 1 boat very hard to know. So, sure you can take your chances, place the bet that you are a better sailor than the current J/99 and will therefore be super competitive, or you can take basically no chances and get a boat that clearly performs well DH in IRC across a number of boat owners.
Perhaps the better question is looking for examples of the J/99 performing well in IRC DH. I'm only familiar with IRC in the Solent. Nowhere else.