they're great but can be hard work, I've got an old Howard Gem think it weighs about 5cwt 3 gears plus reverse, built around 1972 starts on the crank fairly easy, once going nothing stops it, parts are available but expensive,
in my opinion the best type are the ones that are driven by the wheels rather than the tynes, the ones that rely on the tynes to pull them through the soil are a bit light and you have to hold them back so they dig in = bloody hard work, the ones with drive wheels need a gear box so all that costs money, if you just want one to do an allotment your best option is to hire one or get someone in to do the job I charge around £50 to do a standard allotment and that would practically be ready to plant in. But I live in Wales so bit out of my area