Hi Eddie,
Glad you love the Roadster. From what I've read I think you've hit the nail on the head in that the ARP4 seems to have been mis-represented by Morgan when it was introduced. I have posted previously about this (SS04MOG thread as I had a P4 SuperSport before the ARP4) and won't go over it all again. Suffice it to say drove both Roadster and ARP4 after the P4SS and couldn't get the ARP4 out of my mind. No question the Roadster is an easier drive (and felt faster) and more civilised. But if the ARP4 hits the spot little else will do.
Maybe this sounds a bit defensive and maybe it is. But after 3,000 miles with the ARP4 this year (since May) I haven't had a second thought about the decision to buy it.