Early-production models came with the wrong fuel line filters. My first sample sputtered to a halt after 10 hours of use. I've since put in 30 hours on the new filters without any problems. If you encounter sputtering and a decrease in heat output, call MSR and they'll replace the filter at no charge. Write a field-based equipment review and share your experience with other backpackers.
Simmer function is great.
Very stable even without optional base. It is a flimsy peice of foil, doesn't appear to be durable.