All though when I was in UK, I would have loved the idea of Hoya, having 1.2 stops reduced, vs. the Heliopan which cuts close to 2 stops. For my use, I am more than happy to get a 3 stop or even a 4 stop if I could!
Only this morning, at dawn, I was out shooting and I've had to compensate for the sun by putting in manually -2EV and even then bracketing a bit more to get a further -0.7EV! There really is something like too much sun

(that's not a cool similie).
Then there is the issue of cleaning; I was surprised to read that Hoya are easier to clean, but that makes sense since the ones you are talking about are very recently made I believe. From experience, the Hoya were the worst to clean, followed by Nikon, while Marumi were the best of the lot :shrug:
There is another reason to favour the Heliopan & B+W over the others, and that's if you go with the Kasemann range of Circular Polarisers, these are far better sealed and made of brass. The better sealing means less possibility of condensation forming between the two layers. The brass ring means far less likely to get jammed to the lens.
Then there are a couple of reasons why I prefer the Heliopan over the B+W; 1) it is less known, and hence doesn't get me that "snobby" look; 2) it has the incremental markers on the bezel which makes it easy to remember what angel I used.
Now, and in all fairness, I don't know much about Hoyas' new iteration, but by the sound of it they may be competing well.
On your last sentence, about Cosina, does that apply to all Cosina lenses, since they also make the Voigtlander too? If that's the case, then let me just say that they make some of the sexiest and amazing bit of glass. I used the 20mm exclusively this morning, and what a piece of art that is.