Hello Vox players. I have a 1990's AC15 (not the new CC1 or CC2) with the stock Vox Bulldog speaker. I've always been happy with the amp's sound. However, I keep reading about how the Celestion Alnico Blue is the greatest speaker ever, especially for the Vox. I'm wondering if I should buy one and try it out. They're expensive. For those of you who have played both the Bulldog and Blue, is the upgrade worth it? Or if you have a Vox with the Blue speaker(s), would you say do it? Thanks.