Here are the main points of difference between the two STB, 1-8 refers to Vesta 8300:
1..Sound quality appalling. If it will be used as a multimedia device to play mp3 and high quality sound from video files this product fails. Firstly, its output even when on full volume is well down on ANY stb I have used previously. To get reasonable volume sufficient to drive TV or Home Theatre, its output must be cranked to full, and then it distorts. This makes it unacceptable when playing music via Home Theatre, and just acceptable when used as a video source as movie or off-air.
2..Picture quality is poor compared to Digistar when using SCART as component out. The picture is typified as bland, with little sharpness so that detail is lost. Colour tones are fine. Its composite video is good; seeming to be superior than its component!
3..Picture scaling is faulty; often with odd sized source eg off-air, it struggles to get the perspective right on any of the 4 settings. Conversely, the Digistar had no such problems.
4..Menus are better than Digistar but thats personal preference.
5..Plays USB video better than Digistar, eg Digistar did hickup and reject a couple of AVI files I threw at it, whereas the Vesta had no such problem.
6..Delay before functional if USB has eg 500Gb USB drive, can take about 15-30 seconds before any menu operations are available. Can be confusing for new users as they can think the STB has locked up. Digistar didnt have this weakness.
7..When off, displays OFF rather than clock which doesnt make sense; IMHO if no clock, should show nothing.
8..Can record one channel while watching another (same frequency; its not dual tuner) also has delayed play while watching. Both these features unique to Vesta.

Notes (applies to both):
If AVI file have subtitles seems no way to disable them with either of the STB.
Can't read NTFS format, so you need to format your USB devices with (recommended) FAT32.
Neither can play .mkv files.
Digistar has had several firmware updates since I purchased it 2 years ago, whereas the Vesta has had one to my knowledge.
Digistar has been easier to get support if needed.

There you have it. Remember this review is my personal opinion only, and I have no affiliation to these products apart from owning them. If anyone finds some of these comments incorrect, please advise and I will be more than happy to amend if necessary.
Kind regards,
Alistair.