I'm thinking of going to HDV using a Sony Z1 and have been looking at my post/NLE alternatives. The Cineform solution of converting the m2t files for use within Premiere looks pretty compelling. How does this workflow differ from how Avid Xpress handles HDV video? They don't talk about using a DI and claim to edit HDV natively.

Anyone have input on the advantages/disadvantages of these two solutions?

In Premiere Pro, you have either option. Assuming you have the processing power, it actually does a pretty good job in native editing. I have a dual core AMD system that is pretty generic, with 2 gb of memory, and I am getting pretty good render times. Cineform claims better color rendition in using its program. Be prepared to ad lots of hard drive capability as Cineform inermediate files go 4 to 5 times size of .m2t.

No doubt that Cineform is MUCH more robust than editing HDV directly - ie M2T files in MPEG2. This is VERY visible if you do anything else than "cut-edit" the degradation is terrible with MPEG2. Specially if you plan multiple generations. Almost same thing with DVCHD PRO.