W2 dual pattern head header options

blue missile said
#1- find a header that fits
#2-buy the W2 flange
#3cut the LA flange off and weld the W2 flange on
Andrew

Seeing that tti makes good quality w2 headers that fit my car why would you go through all that trouble.
My only real question is if anyone had success using the standard LA flange on these heads without a big performance loss?