the BLM website for the gorge gives recommended flow for raft sizes. BLM recommends a 12' raft or smaller for flows in the 300-600 range: BLM Boating Gunnison Gorge
based on my past runs, i think it would be tight and technical in quite a few spots at the current flow and there may even be a few walk and drag spots below the gorge before getting to leroy's.
we R2'd the gorge in our culebra in 2009 at a flow of 1100 +/-, and there were a lot of fishing rafts there that weekend. i think that flow would be pretty close to ideal for fishing. based on that run and some past kayak runs at lower flows, i had decided that 800 was my personal low limit to take my 12' NRS raft/frame down. my 2c based on my past experience, but it sounds like tutu has a lot more runs than me.