Hi yakapo - I'm a micro 4/3 guy, but if you're willing to buy a fixed lens
RX100 for $648 new (or
$519 used) with a 1" sensor and give up the EVF, you might as well get an APS-C
Canon EOS-M with the 22mm lens for $469 new (or
$439 used) plus the
EOS to M mount adapter for $159 new (or
$119 used).
That way, you will get the same quality photos and video you currently get from your
T4i in a
much smaller package, and you'll have the option of using your
T4i lenses on your travel camera when the need arises.
The challenge with the
EOS-M, though, is that it doesn't have a built-in flash - so you would have to carry your
420EX for low light situations.
If that doesn't work for you, and you want a 4/3" sensor, interchangeable lens camera with an EVF and a built-in flash for less than $500, the
Panasonic G5 with the 14-42 kit lens for $498 (or
$415 used) is a great option. This is a great still/video camera that can produce images like
these. And video like this:
[video=vimeo;64764145]http://vimeo.com/64764145[/video]
The
G5 is also significantly
smaller and lighter than your
T4i.
The
G5 was just replaced by the slightly-upgraded
G6, so they're throwing the kit lens in with the
G5 for free to close them out (the body only and kit lens prices are the same). This camera will sell out quickly, so if you want one, you should jump on it.
Hope this is helpful!
Bill
Hybrid Camera Revolution