In general, the 1480A has the same features as other USB protocol analyzers with the exception of hardware filtering, external triggering and class decoding functionality which currently is not supported by the 1480A. These are features that few need so we left them out in order to keep the price very competitive. Especially class-decoding is expensive to implement and test due to the large number of device classes defined (camera, disk, HID, Serial etc). We have considered creating a separate for-pay package that adds these seldom-used features but so far the requests have been few.
Note that class decoding will not benefit analysis unless your device happens to be part of a particular device class. For instance, a disk class decoder will decode SCSI command blocks automatically while the 1480A would display the raw hex data captured instead (manual decoding of disk command blocks would be needed). Most custom devices define their own endpoint protocol on top of the basic USB IN and OUT Transactions so no class decoders are needed for most custom USB devices.
So in short, if you require hardware filtering, external triggering or class decoding then you may have to go for a more expensive protocol analyzer solution (about twice as costly as the 1480A). Note that the class decoding is not part of the USB 2.0 specification. The 1480A is fully compliant with USB 2.0 and will decode all information in the base spec.