jherch, anyone telling you they can "feel" a difference in speed when comparing aero wheels to non aero wheels is talking BS.
The difference is there but it is so small it can not be instantly "felt".
An aero wheelset will save you a few to a bit more than a few seconds over let's say 20k ... that's it.
A lighter wheelset will save you some time on hilly courses and will speed up faster ... that can actually be felt but even then the difference is small at best.