Just to simplify things...... for the Replay users that are considering a digital to analog converter box (without having to download software modifications, etc.)
From my personal (extensive) experience (with a 5000 series unit).
Compatibility may differ with other series' Replay or Showstopper units.
Listed in order of overall performance:
Channel Master CM-7000 (uses code #0144) - Excellent performance overall. Best for weaker signals. Picture quality excells over all other boxes tested. Front panel switches are glitchy (not an issue for most users but can be quite annoying if you need to use them). Has S-video output. Remote control is larger than necessary, with extra buttons that don't function (strange!). Larger than average unit. Build quality seems better than average.
Digital Stream DTX-9950/DSP-7700 (uses code #7470) - Very good performance overall. Not quite as sensitive as the CM but will work well in most situations. Channel changing (using aforementioned code #) is swift and doesn't lag on previous channel. Remote control is better than average (but cluttered). Very small unit.
(Not recommended that you use this unit in same location with Channel Master or Apex, as remotes codes interfere with each other)
Dish Network "DTV PAL"/TR-40CRA - (uses code #7775) - Good picture quality (although this can vary from one channel to another and in some cases, PQ is worse than average). Sensitivity is good (similar to DS or somewhat better). Best on-screen displays and EPG (although EPG can be unreliable, with limited program data for some channels). Has various known reliability problems with clock and timer functions (if being IR controlled by Replay, this is of no consequence). Remote control is better than average (but cluttered). Very small unit.
Apex 250/502 (uses code #7470) - Decent performance overall but has some sensitivity issues and produces pale color and a (slight) greenish cast. Overall picture quality only decent. Limited recommendation. Channel changing (using aforementioned code #) is swift and doesn't lag on previous channel. Has S-video output. Remote control is worse than average. Larger than average unit. Build quality seems better than average.
(Not recommended that you use this unit in same location with DS, as remotes codes interfere with each other)
RCA DTA800B1 - (can't recall code #) - Poorly performing box overall (both sensitivity and picture quality were worse than the above). Tends to lock up and requires removing and reconnecting power. Remote control is better than average and very user friendly (with larger than average buttons and less clutter than others tested). Can be used in upright position (can be stood on it's side). Small unit.- Not recommended (for Replay users and in general).