There are two audio XLR channels to use with the A1. But what if I want to use a XLR mic input on Channel 1 and ambient sound from the on camera mic on Channel 2? With the A1 it seems to be an either/or scenario. You either use XLR inputs or the camera's mic input. Not both at the same time!
Anybody thought of a work around?

Canon changed that in the XH A1s, so you obviously aren't alone in this desire.

Park a Sennheiser ME67 shotgun (substitute you're particular favourite shotgun here) on the top of the camera linked to XLR (take you're pick).

Stick you're remote (by whatever means) into XLR other - hey presto, job done.

It's not a limitation, it's an advantage - forces you to take the sound "off cam". Works for me and countless others.

Else, as Curt says, spend the deniro and pony up for a "S" series camera. Not much point complaining about the design of a two year old (on the market) camera when it's already been thrashed to death on these boards, and it's replacement has been announced.

CS

Most professional cameras outside the 1/3" chip units don't come with a built-in mic but they come with a mic holder, as the XH A1 does. You stick a short shotgun mic on there and, as noted above, you can use it for ambient sound while using a second mic for whatever. The built-in mic isn't good enough for much of anything anyway--I don't even know why they put it there.