I have a Honda HRB215HXA mower that was the top of the line residential unit with Hydrostatic and blade clutch when I purchased it 13 years ago. It still works fine but I have always wanted more power. I have a large lawn much of which is on a hill or in difficult areas. Also living in the Pacific NW means that the grass is never dry, even in the summer most of the time. Between the moisture and often waiting too long to mow I have always wished this mower had more horsepower. I was looking at the new HRX217HXA mowers and notice they are rated at 6.5 HP, as mine is/was rated at 5.0 HP. The thing that baffles me is that mine has a GXV140 engine which from everything Ive read appears to be a commercial grade engine. The new mower now has a GCV190 engine, which I believe is more of a residential grade engine. Would this mower be much of an advantage over the mower I currently have when it comes to blasting through tall wet grass? What are the differences between the engine I have being a commercial unit and the new mower engine being a residential unit? Is this a lesser quality engine regardless of overall power that will not last as long? That being said I was also eyeballing the HRC216 commercial mower, strangely enough if I recall correctly it is only rated at 5.5 HP. Is this a deceiving rating? Why would the commercial mower at $1249 have less HP than the $699 residential mower. What are the differences and advantages to the commercial mower and related engine in comparison to the residential mower/engine? Thanks, Mike.