I've got a whole article about Orange Squeezer clones in my reviews page, along with reviews of various specific OS clones. Also note that Levin has used an OS but he has also used a variety of other compressors, and was known for using more than one compressor at the same time on some recordings.
I've caught Tony live in small settings... and live he's had a bi-comp on the floor. I wouldn't call it a 'smoothing' effect, and yes it colors the sound quite a bit.
