What lens is it? Likely, it won't be very good compared to a modern design.
Thats a load of horse shit. I'd take an old Canon EF mount any day over a similar current gen lens simply because the IQ would be at least as good, and it would be less expensive. Inexpensive lenses produced today tend to be much "cheaper" that is made with plastic and not solidly built, etc.
Canon EF series hasn't really made a bad lens. Some say the nifty-fifty is poor, but honestly its so cheap that it doesn't matter that you can only drop it exactly once before it breaks. THe IQ out of that $100 lens is so awesome that its a no brainer.
The photographer makes the picture by the way. The camera is a tool in his/her arsenal. Just as the canvas and paintbrush and paint do not make the portrait.
The 75-300mm is slow but usable in daylight, and for stuff like the zoo. Don't even think about doing dark concerts or anything like serious action sports. at f/5.6 at the furthest zoom its really not gonna happen.
the 18-55 EF-S is the kit lens. You can expect kit lens quality out of it. Its a good lens.
The difference betwixt the EF-S and the EF is that the EF-S is the "short focus" version. Because of the smaller (relative to the 35mm frame) APS-C sensor, the closer proximity to the sensor yields an identical effective focal length.
The EF-S lenses fit only the xxD and Digital Rebel series of cameras (i.e. Pro-sumer and consumer level - the xD is the Professional level and won't take an EF-S because its sensor is full-frame). The distance between the rear of the lens and the sensor is shorter than for EF lenses. It's possible to reduce the distance on those cameras because they have a sensor that is smaller than 35mm, along with a smaller mirror. If it were possible to attach an EF-S lens to a "full size" digital camera, I suspect the mirror would crash into the back of the lens when it comes up.
Honestly my wife doesn't use IS at all. If something is at that far of a focal length or dark, she just whips out the tripod and gets a better picture anyways. Besides she uses mostly older L lenses without all that mumbo-jumbo.
I find it useful on the 55-250 lens doing wildlife. It corrects "your" camera shake from your hands by a couple stops. It doesn't fix the vehicle you are ins movement, it doesn't fix subject movement. So say you have a shot that is properly exposed at 120mm f/8 1/100. Common sense says don't take it, 1/100 is slower than the 120mm focal length so is likely to be blurry due to camera shake. It's less than a stop off so you can just flip on IS and take the shot and it'll be fine. The brand spankin newest L lenses have 4 stop IS so in theory you could take one at 250mm f/8 1/50 or so.
Take all that with a grain of salt though - your SO is not my SO, and your needs differ. I still use a Digital Rebel XT (hand me down from when my wife was not a pro) - she's moved on and does a lot of film now, but still uses digital daily with a pro level camera.
I find the whiz-bang features are a bit overwhelming, and the most important thing that you want out of it - is a picture. Will the gadgetry help you get the picture or will it get in the way? A lot of photography is learning how to see and exposure. I bet she won't miss the features in the T1I at all. HD video is great but IMHO is a gimmick.
Also - though great strides are made: Generally speaking more MP is more noise and thus less usable ISO. In my wifes old 50d that sits on a shelf she found that out quickly. Compared to the 40d it is a full stop or 2 less usable on ISO for a couple more MP.
10.1 is a LARGE picture and on the XS you can easily get an 8x10 crop. My XT has 8MP and serves my needs just fine (that is to pretend I'm a good photographer and wish I had the talent that comes inherently to an artist such as my wife).
