While I haven't used 1Password on Windows, it's come a long way in the last year or so, so that it's now a first-class cloud-based password manager with sharing, sync, and cross-platform clients, as well as the ability to belong to multiple organization-level accounts at a time (great for us serial entrepreneurs!). 1Password's Mac browser plugins actually communicate with the native client running in the background and doing the heavy lifting, which I think is a better security model as the plugins only need to worry about securing the localhost communications channel, rather than securing any data caches or doing any cryptography themselves. I've left LastPass entirely, and good riddance.