The difference isn't with the ECUs themselves (they're almost identical from what I know) it's the program and maps on the chip that give the difference.
I know of two chip variants used with the 141 ECU - the '097/BF43 (used in 75 and SZ) and the '737/9AE3 which I have listed as being for SZ only - but I'm pretty sure that's wrong because it's a much less performance-orientated tune - unless it was crippled for a specific market, but it's more likely that it was for a 75 or 164....
For the 164's 117 ECU I know of 4 chip variants - '710/02EA, '310/49F3, '096/49FF and '482/5CB4.
Each one of those will behave slightly different - I would imagine the rev limiters are all pretty similar (except for the '097 which has the soft limiter set to only a few rpm less than the hard limiter - it's the for the SZ after all) but the maps for fuel, spark etc will all likely have small differences. I don't know what year/market each of the versions goes with, but would't be surprised if certain markets like NA, Japan, Switzerland etc got different maps to other parts of the world to meet specific emissions requirements, speed limiting etc.
It's a similar situation with the TS - there was only one type of ECU used (the '108) but I know of 7 different chips that were used, and each one behaves differently. Some differences are only minor, others would be quite noticable though.
If your rev limiter is set to 7200, then I assume you have an aftermarket chip fitted, i.e. Squadra or similar. In all the factory chips I've checked, nothing came stock with a rev limit anywhere near that high. Even the SZ has the limiter set to only 6600.
Without knowing the chip numbers in the two ECUs you used, I can't really do much in the way of a meaningful comparison - for all I know you could have had a '097 chip, which is the black 'SZ' part of the comparison maps I've posted recently. That one would be a
very noticable difference over a stock chip/ECU
