I have a Toro 20192 which is basically a Lawnboy deck with a Honda 160 engine. It is on its third year now and works great. I cut about 23 residential yards a week with it. Thinking of replacing it next spring. My question is, does the new 22156 Commercial 21 have a different (stronger) transmission than my 20192. Toro brochure doesn't give much info. It just says it has single speed rwd. Thanks in advance.