[Google Chromecast] Asphyx:
Hard to say if Plex will solve that pausing problem or not. Could be happening for any number of reasons not related to the app or casting method being used and be all about bad network and CCast connection.

Plex being the better option with Plex server for all that transcoding goodness still suffers from the same Pause and buffering issues from time to time that aVia will suffer from, the only improvement being it should happen less and it won't be because the source file is incompatible.

But lets be clear, both Plex and aVia will seem very much like Beta software at times because both are still working out the kinks on the CCast side of things with their systems. aVia has already released a number of updates to their Player and Plex has mostly focused on the Server/Transcoding side of things.

Plex still suffers with bugs in the control protocol where the control device will lose connection but not pick it back up properly without restarting the media from beginning and then manually going back to where you left off, and the Transcoder on the server side is still not at 100% as far as the CCast profile is concerned. Surround is not working properly for CCast in the Transcoder and it may still be having some issues with source files that are at such a high VBitrate that the transcoder can't really keep up. Plex Devs are aware of these problems and are working on them and I suspect thats Reason #1 why they are limiting CCast support to PlexPass users right now as those users are much more familiar with the system and don't want to deal with the onslaught of complaints they would get if these bugs were released to a wider audience as is.

aVia on the other hand is probably a bit more mature in regards to control and connection since their methodology doesn't require a lot because it merely takes in data and spits it back out to the CCast. But this is also why some files simply won't play well on it when sent to a CCast. I'm not sure what plans the aVia Devs have but they could really improve the CCast support if they did some minimal transcoding in the same way the GoogleCast Ext (Chrome) does to make any stream coming in fully CCast compatible. Not sure if most mobile units could handle the task of transcoding without burning through your battery but it would make aVia much more flexible in what it can send to the CCast.

It's apparent that for the $35 price point that the CCast has a very narrow window on what it can play problem free and it certainly is not robust enough to play from content libraries that have very high quality content without transcoding. Most people with large libraries also tend to favor MKV containers due to the fact they can support subs, Multitrack Audio and any Video or Audio Codec.

It is this ANYTHING GOES capability in MKV that always makes it difficult to get transcoding right. and unfortunately it's that same versatility of MKV that makes it impossible to support those container types natively in Hardware. There are just too many Codecs that it would need to have onboard for it to be practical.

That said I would love to see a NextGen CCast support MKV/H264/AAC natively and regardless of container type if the video is H264/AAC just play it without the need to transcode. It probably supports those files now but there is no option (save maybe aVia) to play them to CCast without Transcoding as I write this.