I more-or-less just retired my T4 and replaced it with an X100T but I thought I’d share my thoughts on this cult classic.
Amazing camera. There are reasons why it’s so popular. The autofocus is almost always spot on- as long as you use the center focus point and halfway-press the shutter (also locks the exposure). The T4 is programmed to use a higher shutter speed rather than to open up the aperture, giving the shallowest depth-of-field possible (the 35mm look everyone loves).
Although the maximum shutter is only 1/360 (or 1/700… I can’t find a definitive answer), if you use it right you can shoot action photos… The only problem being that as the battery gets older, it takes longer to fire- I could never <em>really</em> get the timing down. This was kinda the only downfall for this camera, in my mind. That and every time you close the cover on the lens and the camera turns off, you have to toggle back to the no flash option or else the flash is automatically fired (if needed- the camera is fully automatic. I shot mostly natural light with it but the flash is dialed (think Terry Richardson)).
The glass is amazingly sharp. When you shoot a portrait with a face in the center of the frame, you can see details that you never even knew were there. The lens is reasonably fast (f/3.5, not as fast as the Stylus Epic’s f/2.8 (which also boasts a maximum shutter speed of 1/1000 but is riddled with autofocus issues)) and the 35mm focal length is ideal for point-and-shoot scenarios. It is fairly compact- I used to carry it in my pocket at all times… not comfortably or fashionably but fuck it.
The T4 is optimized to be used with ISO400 film, whatever that means. I shot with everything from 100 to 3200 and never had problems. I also dropped the T4 a bunch of times and the back started to leak but with some (lots of) electrical tape, the issue was resolved. Super durable camera. Great camera. Amazing camera.