After much deliberation, we settled on the MTD T245 hoping it would be big enough for larger areas, adjustable to smaller areas, manageable by my wife and easy to transport to and from the allotment - it does them all! Assembly was straightforward, my wife and I lifted it easily up the garden steps, it started 1st pull and easily and then rotavated deep and to a fine tilth - perfect.
Up at the allotment, it did larger areas with ease: once the rear spike is dug in, I can manage the machine with two fingers, you just lift the handles a bit to allow it to move forward a little and on you go. None of that desperately holding on to runaway rotavators. My wife can start it (no faffing about with primer bulbs etc) and use it easily. It goes up the ramps into my van easily (but see comment about wheels).
Only criticism is that the transport wheels would be better if they were larger and on a longer axle - moving the machine around over rougher ground at the allotment is a a bit awkward as it topples over fairly easily. Would I buy another? Definitely!