Interesting, considering they would most likely accept yours.
Concerning the OP: The method is not nearly as important as the ritual and the condition of the heart of the individual. While I agree that immersion is preferred, that doesn't mean that the other methods can't, won't or don't accomplish the same purpose that immersion does.
I don't believe churches should require people to be rebaptized simply because their original baptism occured in a different denom. That's almost like saying they aren't saved because they weren't baptized "right". Instead individuals should be instructed in our beliefs about baptism and if they believe our purpose for baptism were accomplished in them originally the decision to rebaptise should be left to them.
You don't believe and wouldn't expect that the church at Ephesus rebaptized believers fleeing Jerusalem. Why should we then require one who is saved and baptized, albeit in a different manner, to be baptized again? Scripture says:
Eph 4:4There is one body, and one Spirit, even as ye are called in one hope of your calling;
Eph 4:5 One Lord, one faith, one baptism,
Eph 4:6 One God and Father of all, who is above all, and through all, and in you all.
As Baptists we don't even consider baptism to be a part of salvation, why then do we bother so much about the mode?
My baptist Church does NOT have it as an absolute requirement for membership, but we do emphasis it as being Biblical and required in obedience to the Lord to be baptised as a believer in Christ...
Does NOT save you or add to it, but as way to meet obligation God has commanded us to observe, to be Baptised in Immersion...
Many of my Church were originally Roman Catholics who became saved and joined the baptist Church, and most of them decided to redo Baptist now as believers in order to have a "real" baptism moment/experience!