My home roasting years ago started on the Fresh Roast SR500 and I always liked the unit. It is still in use today. Today my new SR540 arrived from Bodhi Leaf and I took it for its first spin. Very impressive! The improvements over the SR500 are significant in all areas: a larger roast cylinder, more roast options and a quieter motor. Not only did the unit arrive fast, the staff at Bodhi Leaf included a great selection of green beans that were included in the purchase price. Very excellent service, thank you!