I recently purchased a bike to get some exercise, and I also plan to take my 2 year old son with me on rides. My preference is a child seat, but I know it's not the safest way to carry a child. Also, I'm not certain a child seat is compatible with my Electra Townie (I have another post regarding this). Anyways, I am also looking into bike trailers. The question I have is regarding wheel types...aluminum or composite. I have noticed several used Burleys for sale with composite wheels. How does this affect the ride? Are aluminum wheels a much better ride or is the difference negligible?