I daily drive a near stock 1997 Acura Integra GSR and a 1992 Civic with a B18B1 engine / ITR transmission swap. At freeway speeds, both were screaming over 4000 RPM. In deciding whether to swap to a longer 5th gear, I wanted to know how many RPMs less it would make at different 5th gear cruising speeds.
I confidently recommend this swap on all daily driven B16 and B18Cs. Driveability has not suffered at all. The drop from 4th gear feels normal. Cruising RPMs are still high, but the exhaust is more of a hum than a scream. Don't opt for a GSR 5th into an ITR transmission. Go for the LS 5th.