I'm interested in buying a wheeled backpack, one that meets carry-on
requirements (22").
I'm especially interested in those that have a detachable daypack.
I've looked at several (especially at ebags.com, and also
baggageforless.com) and
am seriously interested in a High Sierra AT-205.

Does anybody have any experience with this type of bag? Pros? Cons? Are they
too heavy to realistically carry on your back when loaded? I already use a
backpack
from Rick Steves, but am looking wheeled convenience some times.

Any suggestions (for specific makes/models or websites) and opinions are
appreciated!
Thanks in advance!