I've got a model with iteration that runs fine from within ModelBuilder. In fact, I'd say that it is downright zippy taking about a minute for every 5 rows in a raster attribute table. When I run that same model as a tool using the same datasets it grinds to a halt getting hung up on iteration 3 or 4. Specifically it is the Cell Statistics tool and I'm using feedback to save the results from one iteration and then add the results from the next iteration and so on. I'm wondering if anyone has any idea what would be different enough between ModelBuilder and "tool mode" to account for such a large difference in performance. I'd hate to have to share a tool with others with the caveat that it can only be run from ModelBuilder especially when it is working so well otherwise.