I think most folks would say hardware conversion is superior to software. The Kona 3 is excellent if you capture material from tape (or another device). Also, it has hardware acceleration for DVCProHD (it takes over the scaling from FCP which doesn’t do a great job, anyway). The best hardware converter (of all sorts) is a Teranex. But, due to its cost you usually only find them in large facilities. I’ve used Instant HD and was not overly impressed. I use Compressor for SD to HD file conversions.
John
MacPro 8-core 2.8GHz 8 GB RAM OS 10.5.8 QT7.6.4 Kona 3 Dual Cinema 23 ATI Radeon HD 3870, 24″ TV-Logic Monitor, ATTO ExpressSAS R380 RAID Adapter, PDE enclosure with 8-drive 6TB RAID 5
FCS 3 (FCP 7.0.2, Motion 4.0.2, Comp 3.5.2, DVDSP 4.2.2, Color 1.5.2)
Pro Tools HD w SYNC IO & 192 Digital I/O, Yamaha DM1000, Millennia Media HV-3C, Neumann U87, Schoeps Mk41 mics, Genelec Monitors, PrimaLT ISDN