Hi edsm,
sorry for the delayed reply.
If you look
here there is only a £67 difference in price. Only you know whether you need or want the still pictures function - personally I would say it was worth the extra £67 as if you were to buy a digital still camera seperately it would cost you a lot more than that.
The picture quality is average, it is not crisp and clear, but it isn't terribly bad either - I wouldn't recommend it for printing out, but it is more than good enough for emailing etc.
The 18E also offers the ability to record a moving image in MPEG onto the memory stick - this means that you do not need to cpture the footage onto your pc, you just download it from your memory stick. However, you only get an 8mb memory stick with the camera which cannot fit a lot of footage onto it. You can buy up to 128mb memory sticks seperately.
DV-In means that you can record back onto your camera from your pc after you have edited your footage.
Hope this helps,