Depends on what you want. If you can live without SCSI then I'd go for the Viper. It's new and still produced and supported, so it will have a warranty. And for the price of second hand Blizzards you can almost buy a Viper one.
Performance will probably be the same, but there are no benchmarks so if you prefer, don't risk and ask the seller to run some benchmark tests before you buy. I bet the performance is the same though.
