I use the Heralds in my teaching workshop. I've not used the Jet but the specs are similar but with bigger bowl capacity on the Herald and slightly longer spindle capacity on the Jet.
I've heard people complain about the time the Herald takes to speed up and down but I think those people really need to reassess what's important in life! The only other complaint I've heard is about the position of the locking lever on the tailstock being awkward to get at but I've not found it a problem.
Things to note though!
The Herald only comes with a medium length tool rest whereas most lathes come with a long and a short. If you do spindle work it is worth getting a longer rest for it.
The tool rest adapter for off bed bowl turning is not included and has to be purchased at extra cost.
I have to say I'm very happy with how the Heralds are standing up to the abuse they can get from people on beginner courses!