Excellent, I don't know why there are a few negative reviews on here, they must be spoilers! I have heard the audio recordings of these 3 episodes and these 3 re-recorded video versions have hit the mark, spot-on.
The cast are pretty good, they will never be as good as the original, but that is not the point and no one (particularly themselves) would expect that, but for stand-ins they are excellent, Kevin McNally plays Capt. Mainwaring pretty well, and if you pay attention you will see some subtle inclinations and a little pomposity which Arthur Lowe made his forte. Robert Bathurst does a good Sgt. Wilson. Timothy West is as usual a top link, as Godfrey, The rest are not quite as good but still do very well as the other characters, none are poor. The writing is as usual from Croft & Perry, excellent, because they are using the original scripts and scenes, you can't really go wrong. For some reason the modern sitcoms just can't crack quality like this.
You will never get the 100% perfect Dad's Army, But this is as near as you can get, so I give this 9 out of 10.
P.s. the recent Dad's Army film was pretty good, not as good as these 3 but still good.