It’s the same for me. The technical aspect of such linking and trunking is interesting as a problem to solve and to keep running, but using them as the end purpose doesn’t float my boat.
That is £64,000 question. It depends on the modulation scheme, the vocoder and the protocol.
The modulation scheme (4FSK or GMSK) will let you calculate a BER (bit error rate) for a given signal strength. The vocoder data contains voice data and FEC (forward error correction) data. You can use the FEC to fix errors in the received voice data. The protocol lets you calculate how well the receiver stays sychronised and how quickly it can regain sync.
Wide mode Fusion uses twice the bandwith than D-STAR so it can transmit twice as many bits of data and send a higher quality voice signal for the same coverage. DMR fits 2 signals into the same bandwidth as wide Fusion. So you either lower quality voice and lower performance with weaker signals.
Both DMR and Fusion protocols have improved massively on sync performance and recoverabilty over D-STAR, an advatange of coming after D-STAR was in the field demonstrating sync issues!
Simulations and tests suggest a 4FSK signal in a 6.25kHz BW has the same performance as narrow band analog FM in a 12.5kHZ channel.