IMO it's really, REALLY hard to top the Crack+Speedball with the HD 650, particularly at the price point. My 650 sounds great with the HA-1 as well, but that euphoric tube sound that I get with the Bottlehead is seductive and hard to let go of. However, good luck finding a HA-1. Your only option is to purchase used, if you can fid one, or a very expensive new unit from an eBay seller, typically in Japan. I have no experience with the Woo.