The Benchmark is a very good DAC. Sound preferences are a different story. Synergy also plays a big part. In my Bryston and Audio Physic system, the Benchmark would be horrible. Everything is too revealing of it. The Benchmark sounded very etched and strident in a dealer's Bryston/AP system. In a Mac/B&W system, it sounded great.
The BDA-1 is very honest, yet remains smooth and musical. A very interesting and delicate balance that works magnificently IMO.
I tend to shy away from anything I can't hear before buying, unless I can sell/return it for little or no loss. Synergy will make or break a source or any other component IMO.
I've heard the entry level DACs and wanted them to out perform my Rega Apollo. I'd have been able to sell the Apollo, get better sound, and have a few bucks left over for a new CD or three. Needless to say, the Apollo hasn't been replaced. I think the CD5x is a good deal better than the Apollo. It would have been my next upgrade had the whole music server thing not been my latest foray.
Everyone's ears are different. People rave about the V-DAC and call it a giant killer. I have no idea what they're used to. Its great for $300, but won't come close to replacing any decent $1k-ish CDP I've ever heard. Same can be said for the DACmagic and PS DLIII.
Just my opinion.