My 2005 34T and I are just getting acquainted. Single Yanmar 370 runs 8 mph at 1600 rpm, 20 mph at 3400 rpm. I just drove it ~1100 miles from Joliet Il to Knoxville Tn on less than 400 gallons of fuel, mostly at 1200-1600 rpm with consideration of 5-6 mph following current on the Illinois and Mississippi Rivers. It throws a considerable wake at > 8 mph that upsets small boats on the rivers, so 8 is my economical cruise speed. I didn't find it uncomfortable on the flybridge except in the angry 3 foot chop passing St Louis. As with all 'affordable' boats, there are some things that I think could have been designed/constructed better, but overall I'm happy with mine.