My wife & I have been over to ride in the US a few times now and this last time we rented bikes through Eagle Rider via an agent here in the UK. We're both around 5' 6" so we dont feel comfortable riding big Harley's or similar, and to be honest the kind of roads we enjoy riding we just dont need the sheer bulk. We went for a couple of VT750's, it's all they had in "our size" but they were great bikes and we couldnt have wanted for more ..well, maybe better service when we're handing over nearly £2k ($3100)
To me, many of the rental companies seem to think that customers just want a huge great Harley/Wing, because it's a one off 'special occasion' holiday for some.. it's their dream and so they 'think' big is best. In our case recently, the rental company found it weird that we only wanted "small bikes"..lol..mind you they still charged us £100 ($155) per day, per bike, ours were 4-5 years old and covered in dents & damage, while the HD range and Gold-wings rentals in the shop were like new, low mileage and immaculate, that in itself shows the thought process when supplying middleweight rentals.
With bikes more popular today than ever, and how Japanese, British, German, Italian bikes are such common place on the roads today, we still only have a very limited choice if we want to rent a bike in certain parts of the US.. and it's usually too big and too heavy for what many 'really' need from a bike. To be honest we'd prefer to rent middleweight bikes over the larger ones any day, something we can reach the ground on, be able to push around without getting a hernia, and wouldn't even mind if it was a few years old as long as it was looked after, well serviced and priced acordingly. I don't see the need to have to rent huge great bikes when today's middleweights are so good, so something like an ER6, SV650, CB500 etc would be great.