I would have thought a 35mm F1.4 would be next on the list so am a bit surprised that they went the other way. I have a 35 F2 myself and find it a great size and a great lens.... I'm sure the new one will be more compact and might be sharper but I haven't noticed a problem with the 35 F2. The new one is a bit less costly but not enough to make a difference in the purchase.
To gain a stop of light for less than a $100 is a deal in my books.
I haven't used the 18mm that much.... mostly just playing around the studio with it... those that have purchased it seem to love it.