I find our laurel hedge is the easiest to maintain in the garden. Most years a late summer trim is all it needs to maintain it, though after a warm, damp spring it can need an early summer trim too. The new growth remains sappy enough that cheap electric hedge trimmers do the job without the dimensions of the hedge growing. It is certainly thoroughly dense. Will also respond well to being cut back hard if you let it get overgrown. From small plants will probably take you a couple of years to get a 6 foot hedge, and another year for it to fill out properly.

I have an E. ebbingei bush and I find it trouble. Need to cut it at least twice a year and it is sufficiently woody that tougher tools are required. Pleased I only have the one bush, not a whole hedge of it. It grows very fast. In theory it should have fragrant flowers in the winter and berries in the spring, but our has only produced about 3 berries in total.

I think a hawthorn hedge could be hard and painful work to trim. Also will lose much opacity during the winter. If you want a dense thorny evergreen hedge, that isn't too much work, I'd have a look at the various kinds of Berberis. Some of them are very dense, evergreen, easily trimmed, and thorny. You can have an optically opaque hedge that takes up less space than a laurel hedge. Plus it can have attractive flowers and berries.

There are also suitable pyracantha for hedging, which is evergreen, dense and thorny with attractive flowers and spectactular berries, but being rather woody would be harder work to trim. Again, achieves an opaque hedge with slightly less space than laurel.