I have to agree with Laurent and Jason.
Emersion for sure but overiding everything is the fact that it is a sim. Paddles have no place on old cars. They were never an option in the day. People missed gears, locked up rear ends etc. If i want to drive an Escort with paddles i will drive an arcade game in my opinion. And no, it is not quicker for all the reasons that have been said and probably a little slower at times when a hand has to leave the wheel. Never mind the false shifts etc.
Overall, it is whatever you want it to be. if it is a tool to be quicker and that is all that matters take the paddles. If on the other hand you value trying to be connected to reality then you have no option.
P.S. how can the RSS 1970 V8 F1 not be driven with a H pattern shifter?
Just my personal opinion.