The Sony 3300ES doesnït decode Dolby HD/Plus or DTS HD, only the 5300ES
It does decode PCM Audio Multichannel, which is an uncompressed audio format, which is found on BR/HDVD.
If you use a BR Player, with a blueray title, that has PCM Multichannel sound, you will get that, otherwise you will have the PCM 2 channel, or the "old" Dolby Digital/DTS
It appears that PCM Multichannel, sounds better than the Dolby HD/DTS HD, because itïs uncompressed, unlike the Dolby/DTS HD, but it occupies a lot more "space" in the disc, and not all the BR/HDVD titles have PCM Multichannel.
Honestly i never have the oportunity to see/hear which sound format is better.
Sonically i donït like the Sonyïs amplifiers. They lack of substance, and they are at least here in Portugal, too expensive. For instance, for the price of the Sony 5300ES, i can get the Onkyo 875, or the Yamaha RX V1800.... And for the price of the 3300 ES i can get the Onkyo 805 or the Denon 2808.
Hope i can help