I have a Crown Jewel that rides great -- light, responsive, and comfy on centuries. Got it in part for sentimental reasons (love for an old Fat Chance) and because I wanted to try Ti after riding steel for 12 years. It's a wonderful bike, but I don't believe it's necessarily any better than other, handmade frames in the same price range.

One thing to consider is that all IF frames are custom these days, but you don't actually order directly from the factory -- unless you have some special connection, I suppose. That means you have to rely on a retail shop to fit you and communicate your measurements to IF. You therefore need to pick your shop with great care; if it's inattentive or sloppy, you may not get the bike you intended.

As for sloping or traditional top tubes, you can pretty much get what you want since every order is custom.