So many questions on those...
Dynamic range is pretty low ~90dB. Analogue systems tend to be around 100dB and digital 120dB.
Are these things analogue or digital? The dynamic range would suggest analogue... but the fact that there is a latency even registering in the ms range would suggest digital. Typically analogue systems would be measuring latency in µs.
Things in channel 70 are typically analogue.
Simultaneous broadcasts on 100 channels? Huh? Analogue wise, you can only fit 4 intermod frequencies in channel 70. If you were to use a high density mode (like on the top end digital stuff, that crams 63 channels at 1mW within 8Mhz of spectrum... (more channels, yet reduced range)) you'd only get 15 units in the 863-865mhz space. The output power being advertised on these work out to be circa 31mW.
If they work, they work - although check out the compander, (assuming that this is an analogue unit) especially on bass, as it can destroy your lows and make the high end brittle and harsh.
Some prime BS in this marketing I think.