My 52-plate car had the original software. At speed the gear changes were great - if brutal. Plus there was the down-shift blip which sounded great with Larini back boxes. There was also the hill-hold feature (didn't really do much). However, starting off from standstill was jerky with kagarooing if I wasn't careful, and it was this aspect that led me to having the upgrade done.
So before upgrading the software I tried Maverick's TCU in my car (in the knowledge that he already had the same hardware but with upgraded software). After a short journey I thought it wasn't too bad - soft gear changes and easy pull away from standstill. So I had Emblem do the upgrade (~£240 I think).
Now I miss the brutal nature of the original software. Even at speed (throttle to the floor) the changes seem much slower now compared with the original software. So I am on the lookout for a TCU with the original software still loaded. To date I have found two TCUs at breakers yards and purchased them, only to find they have already been upgraded, and as we know it's a one-way street.
For your information - it is easy to determine whether you have the original software or not (this is for a 2002/2003 car):
When sitting in gear 1 with the engine running, pull up on the left paddle. This activates the hill-hold feature. If it beeps and the display flashes, you have the original software . If not, then you have the upgrade.
I work in the elctronics business and I see no reason why the hardware can't be retro-fitted with the original software. It's probably loaded on a memory device (EEPROM) in the unit. If it is, then a device with the old software should be able to be read, and then a new device programmed. I have a TCU (with the upgraded software) which I want to dismantle to confirm this. But I would need a TCU with the original software in order to extract the EEPROM contents.
Moz