I played around with this strat on Emperor with France. Standard/Normal/Continents.
It is definitely a strong/winning strategy with France. However, I don't think it is optimal, for a few reasons:
1) France has no bonus to religion -- at all -- and this strat basically sinks your shot at religion unless you are certain to use the liberty great person on a prophet. Now, I did this, and it is fine, but just an observation.
2) My main concern here is that you leave a *lot* of culture on the table as France if you go for this strat instead of expanding into cities earlier. I found my culture pace quite behind what it would normally be with France.
Basically, it seems to be the case that you trade culture/faith (and possibly a religion) for significantly increased/early science. Now, if you use this tech lead to hit musketeers early and wipe your continent or to hit education early to get still more tech to go deeper into the tree to get a different advantage, so be it
Like I said, it's a strong/winning strategy.
However, with France, I just think you get a lot more out of the UA if you are settling cities earlier. I like having 4 cities by turn 40, which allows me to clear liberty between turn 60-70, for example.
This strat is great though, thanks for posting.