Pros and cons of SpRecord series A and AU?

Question

Telephony

Good day!
I propose to listen to the fairy tale
"About a rude customer and manager - a red maiden"
The customer lived and was in the world. And he was rude and unfriendly. And one day he wanted to order products from us. And our phone was dug up and the call was made. And he ran into the manager - a red-haired girl who did not really like the rudeness of the customer and the customer was given a turn from the gate. But the customer was not a mistake! He called the Director General and told a fascinating story about how the red-haired manager offended him. So the customer is going to be rude, almost to file a lawsuit for compensation for non-pecuniary damage. But no one can prove anything, because there is no record of the telephone conversation either on his part or on our part. And this question has been standing for a good week. And then a wise thought came to the Director General's mind - to record telephone conversations on external lines (of which there are already 4 pieces, they are connected to an office mini-ATS). And the Director General ordered his faithful subject to find a system for recording telephone conversations for an analog signal. And the faithful subject began to search in foreign Google, but look at the prices, and his choice fell onSpRecord A or AU series . The difference between them is that A - connects to a computer and writes conversations to it, while AU is completely autonomous (they stand like tie-ins on a telephone cable and write conversations to themselves on flash drives internal microSD format). The good fellow is sad, twisted, to choose for him, either one A4 or 4 pieces of AU. Here it Thread.Sleep()comes in a fairy tale, and whoever has read this far is a hero.
Now back to the real world, Neo, and see how deep the rabbit hole goes.

The question is what to choose A4 - in a single box and connect to the computer and from there already steer the records, or put 4 pieces (one for each line) AU. In the first case - more wire (there are already a lot of them) + a separate computer will have to be installed. In the second case - stand-alone devices that just hang out on the telephone line and once every couple of weeks they ask to drop records from the flash drive. Who has come across such devices, tell me your comments about such devices, maybe somewhere there are pitfalls and so on. In general, everything you know :)
PS For the Director General ordered the wise people to ask comments about one and the second device, and then we will choose.

Answer 1

Put yourself an IP-ATS, dinosaurs. So you will remain in the days of castles, kings and merchants))))