There’s a lot more to this question than meets the eye (or ear).
The attack circuitry of all my optical compressors operate by making high surge currents available through the LED; initially, with the older Joemeek circuits, this worked to overcome the very slow response time of the light-dependent resistors (the light cells). Nowadays, this is less important as I use a much faster reacting cell.
The very early compressors used a little transistor array as the current drive, and in the earliest SC2 (the ones with a bevelled edge front panel) the power supply was only just capable of driving the required high currents, so the later compressors did sound just a little tighter because of an improved attack response.
The release circuitry was always a ‘compound’ circuit responding quickly to transients, and more slowly to steady sounds ( this system is usually called ‘auto’ by other manufacturers). This arrangement never changed on the SC2 through all the variants, except on very late SC2.2 models where I think I shortened the release times generally.
One of the ‘secrets’ of the SC2 sound was a little trick that I still use, to make the compressor release time actually shorten just before compression releases completely. This makes for a very odd looking release curve, but is great for compressing drums.
So, to answer the question directly, yes, the old V1.05 still had a slightly ‘soggy’ power supply and is probably the most collectable SC2 nowadays. The later ones had a slightly ‘tighter’ sound due to the attack curve being more controlled.
As a matter of interest, the new P38EX has settings that can duplicate the early SC2, but without the image shift that the early compressors were prone to suffer from.