I don't like an overly thick recoil pad, and I also don't care for wood extensions where the glue joint is obvious. Many would say that the joint can be hidden with expert grain painting. But the cost of that process can equal or even exceed the value of many field grade vintage doubles. Also, the joint may still become visible over time due to differences in expansion and contraction of the buttstock and the extension.
So there is always the other option that hasn't been mentioned... a good quality lace on pad that is easily reversible if you should sell the gun to another shooter who needs less LOP.