I'm a fan of the DAC1 but coincidentally sold mine this week to fund a Slimdevices Transporter purchase.
I would pay an extra $300 for a good USB input on the DAC1. I have a small Dell laptop (XPS M1210) with a 120GB hard drive storing lossless albums, and I love the idea of simply adding the new Benchmark for a high-end two-box solution. I used a Transit in the past, but the extra box (albeit small) and cabling always bugged me. I looked around for a ExpressCard sound card with coax digital output, but none exist yet. (The M1210 only has an ExpressCard slot.)
I can fit the laptop, DAC1, and my E500s in small laptop bag and have 200 lossless albums at my fingertips. Cool.