To be honest the Tunnel is a bit boring if you are not under any time pressure, no facilities actually on the shuttle, there are in the terminals at either end, but given this is about getting across the channel then given fair weather, having a meal on the ferry is a pleasant diversion.
Then we have the tenuous situation with the French strikers that are Calais dock workers and as far as i know the dispute isn’t settled, so that would favour the Tunnel.
The way the Tunnel works you drive through like a toll booth, follow the signs get in a queue go through the French border this side, then drive into the actual train which some find a bit claustrophobic, 40 minutes later you drive off the other side straight onto the motorway system further out than from the Ferry docks, so it is considerably quicker.
Most of us locals (the Tunnel is five minutes from where we work/live) use it thes days, due to the reliability in times of bad weather, indeed I met a bunch of mountain bikers back from Morzine, on the ill fated last trip and we swapped stories as we waited in one of the queues.
So give it a go at least once see what you think.
Edit: Oh and lock your car on the way back, the refugees look a bit scary and will frighten the kids.