Hi Edward
I’ve only looked at the Volt metro but never ridden one. My local Volt dealer would not allow test rides. Compared to a Raleigh Stoweway the Volt seemed a bit awkward to handle when folded. The Raleigh is nice to ride, (my sister has one) but the battery is a bit small.
I would consider looking at the Wisper 806se. Wisper are well respected here on the Pedalec forum and are cheaper than the Volt. Both Wisper 806se and the Raleigh Stoweway/Evo have received good reviews in Which Magazine. If you don’t subscribe to Which your local library may have access to the reviews.
Also consider Woosh bikes. While only mail order unless you are near Southend on Sea, they have a very good reputation here on Pedalec and bargain prices. You could end up saving over a thousand pounds on two compared to Volt and still have good bikes.
It can be quite frustrating choosing the right bike, I ended up with a full size bike instead of a folder in the end, but whatever you get they are great fun and well worthwhile.