I agree with sngsk. It seems to me that the only reason why you're considering a Roma is because you think it might stop your craving because it costs so much. That logic doesn't work for me, and I'm not you--but I don't think it would appease you at all. If you don't have any other reasons to like it, don't get the Roma. You might just end up spending a lot of money and regretting not getting the style you really want.
All of the bags you're considering are what I would call expensive, and every one of them is worthy of your consideration. The most expensive does not always mean that it's the best choice. You even wrote in your first post that you're not going to allow price to factor into your decision--that works both ways.
Now, you say you're considering the Roma, Campana, Sloane, and Pyramid (by this do you mean the New Pyramid?). Anyway, except for the Roma, you're looking at shoulder styles, so that tells me that you're looking for something different than the Montaigne that you already own.
All three of them are very nice, and there are many, many threads of posters asking for opinions of Campana versus Sloane versus (New) Pyramid. You'll undoubtedly find them by doing a search of the board. In a nutshell, 2 straps versus 1? Clasp closure versus magnetic flap versus zipper? Hardware versus no hardware? Only you can answer these--some hate the flaps of the Sloane, but others find it more convenient. Some hate the 2 straps, others find it more convenient. Some hate the puffiness of the Sloane, but others adore the voluptuous shape.
Good luck deciding! This is a fun decision to make. You're lucky to have a boutique nearby so that you can try them all on and make an informed choice.