I've just downloaded Imgburn, since DVD Decrypter doesn't seem to like writing discs on my new Vista PC (it was fine on the Vista laptop, but then it is an outdated program so you never know), and while I haven't tried burning a disc with it yet I was pleased to see it has the same look and feel to DVD Decrypter.
However, I was looking forward to moving across wholesale from that program, and I do think you're rather cutting off your nose to spite your face by not including an IFO read mode. I use that all the time and if others are also asking for it, it seems odd to deny your userbase of that function just because "it's a burning program" - even though it can read a disc to create an image on the hard drive, so it... reads as well.
I definitely think you've missed a trick there and would like to also request it's inclusion, please.