I have had one of these for a very long time now - slightly smaller surface, but can be clamped onto another table to make a more comfortable working height, and has a tool box underneath
Get an old one-mines probably one of the first and has outlived all the others-its bombproof.
As others have said, the cheap ones should be left in the shop.
A Zyliss Vice is better than a workmate in my opinion and they turn up on Ebay often enough at reasonable prices, you just have to take your time and snipe one.
They were called Zyliss Vices but have been re branded with the Z vise name to appeal to the American market (complete with American spelling) but they have been made for years and sell quite cheap.
Great if you already have a bench to attach it to
I've had mine for about 20+ years and I have done everything with it made knives to rebuilding our kitchen. Great piece of kit.