Having grown both versions multiple times (Sweet Seeds), I can confirm there is no noticable difference in quality, size, yields, potency or flavour.
A well grown plant is a well grown plant.
The fast version does exactly what they advertise, they flower about 2 weeks earlier and flower faster than the "normal" version, meaning maturity can be some 2-3 weeks earlier for the fast version compared to the "normal" version, which can play a big difference if early rains are likely.
I do prefer the fast version due to it finishing earlier, as I have lost lots of flowers to bud rot when growing the "normal" version as it can finish quite late in the season..............and with big thick buds, rain is the heartbreaking enemy.
But rest assured, you will not be growing an inferior plant by growing the fast version.