Hi mightyjesse,
Caerphilly tends to have a sour tang to it, which mellows as it ages. It also tends to be salty, although perhaps not as salty as it used to be as fied has pointed out. Personally, I quite like the sourness (which is not overly strong) and find it is the primary taste that defines caerphilly for me. Lancashire does not have this flavour profile, at least none of the ones I've made have. It's also often a crumbly cheese, so a high acidity is targeted during the make.
I've made a caerphilly where I cheddared it a bit longer, and pressed a bit heavier, and it turned out very nicely. At first I thought perhaps it had less of the tang to it, but I later decided it was there just fine. The increased cheddaring and such influenced the texture in positive way. Dave has made a version where he cuts the curds a bit larger and waits longer before cutting (4x floc I think), and he found this produced a very nice moist cheese with great melthing properties, and still had the taste of caerphilly.
It's a quick cheese to make, and it is ready to eat in a couple weeks. It does improve, and though I cut mine at 3 weeks, I do note that it improves as I'm eating it over a few weeks, so probably it's best at somewhere between 4 and 6 weeks. But I recommend trying it at different time points to find what you like best.
- Jeff