I just bought one 2 weeks ago
I bought the 4003 model with a 13.5 hp robin engine and log lifter. I consider it to be extremely fast. I used a horiz/vert model previously and it had a 17 second cycle time unloaded. The iron oak model does 7 seconds loaded, it also splits 4 ways and cycles automatically. With the old splitter it was about an hour per face cord one or two people. I feel that if the conditions were right you could do about 4 face cords per hour with this one. It was $1900 less than the timberwolf TW5 with the very similar specifications. That made the choice easier.