Windsor is a yeast that "grows on you". First time I used it, I hated it, and swore I wouldn't use it again for anything I brewed. I didn't understand how it could be possible to commercialize such a crappy product. At the time, it was an imperial stout I used it in. It finished notoriously high, with sulfur and fruit all over the place. I considered dumping the whole batch, but decided to see it through, thanks to some guys on this forum. After some weeks, the sulfur was gone, the fruit mellowed, I decided to consider using Windsor again. After a few months that imperial stout flavour was really good, and my Windsor reluctance had gone. I have used Windsor several times since, in stouts and milds, but because it does have an attenuation issue, I have added a better attenuator when Windsor is done, to make it finish lower. I used Windsor recently in a mild, OG was 1.035, and Windsor pooped out at 1.018. At that point, I was bottling a dry stout fermented with US05, so I racked the mild onto the US05 slurry, to get it further down. In writing moment, my mild is still fermenting and today SG=1.012. Prior to the mild, I brewed a foreign extra stout. OG=1.076. Windsor pooped out at 1.024. At that stage I prepared a 75 cl. starter with Danstar's new yeast, "belle saison", and added it when active. This took it down to 1.012. When adding a yeast to compensate for your primary, bad attenuation, I have found at that stage, the second yeast does not contribute to flavour in any significant way.