I prefer the TI early on. Love the speed and versatility they had. I seem to have had little trouble with them.
I've mixed in the TII and I've had very little bad luck with them. Mostly prematures in rough seas.
Avoid setting the TII for magnetic fuse early on though.
I don't load the TI's for a normal load out later in the war except for externals, so I still have to use the good ole steamers after I move my externals inside. You just have to be more careful in daytime.