I needed the synth block for one key part of Jesus Christ Superstar. But, thankfully, it's rare for me to need it, even though it's awesome to have it. We're approaching a situation where I may need to sell my Axe FX rig, and downsize. (Darn car accident and insurance companies!)
This is a little off-topic, but, I did so much for that show. No way I could have done everything without my Axe FX. It was a good experience. Challenging, and an overall good learning opportunity. Getting asked to volunteer was a big pill to swallow, given the total time involved and the cost of my gear. (They did give me $100...) But, once you start volunteering, get ready for more. I rocked the gig, and was proud of it. It completely changed the theater's performance, in all honesty.