Will I notice the difference on my Tannoy TFX speakers?
The timing of your question within the thread suggests that you're asking if you'll hear the difference between ARC and eARC. If so, you can test this for yourself. Do you hear the difference between Dolby Digital 5.1 and Dolby TrueHD?
The difference between ARC and eARC is in the formats they support. ARC is the equivalent of an Optical or Coax digital connection. It will support stereo PCM (without or with Dolby Surround encoding as picked your amp's DPL II processing), and DD5.1 which is the lossy 5.1 surround sound format made popular by DVD.
Quite whether DTS is supported by the ARC connection depends on the TV. Some don't feature it at all. Some will pass a DTS 2.0 (stereo DTS) signal. Others will pass DTS5.1. Just a reminder, DTS is the equivalent of DD5.1 It is a lossy discrete 5.1 surround format.
eARC is the equivalent to a step up to HDMI for n audio connection. The difference that eARC makes if fitted to both the TV and receiver is that the connection supports all that ARC does
plus...
Dolby TrueHD - the lossless surround format as used on Blu-ray discs
DTS Master Audio - the lossless surround format as used on Blu-ray discs
multichannel uncompressed PCM - as used by
games consoles, multichannel SACD and DVD-Audio players, and any other source that either won't output a digital bitstream HD audio signal for TrueHD/Master Audio.
In answer to your question then, if you have a BD player with HDMI out and Optical/coax out, and you connect both to different inputs on your 323, then make sure that both are set to output Bitstream, what you should be hearing from your amp is a DD vs Dolby TrueHD or a DTS vs DTS Master Audio comparison.
Clearly there will be times when ARC and eARC will sound exactly alike because the signal is PCM 2.0 or DD5.1 from the source.