Tilling involves a lot of turning around, bouncing off of rocks, etc. Electric lawnmowers are an equally bad idea.
I’ve done a lot of tilling over the years - Front tine, Rear tine, small and large. Also used tiller attachments on weedeaters. I can think of no real life situations where an electric tiller would be a satisfying or useful experience.
I use all corded electric yard tools. Lawnmower, hedge trimmer, string trimmer, tiller, chainsaw, etc. It isn’t a problem - cord goes over my arm or shoulder and away I go without worrying about gasoline or starting. Never had any issue with the cord really.
My tiller is very similar to this and in my heavy clay soil it is necessary to pre-break the soil with a manual tool like http://www.lowes.com/pd_286958-1078-79906935_0__?productId=1080991&Ntt=cultivator&pl=1¤tURL=%3FNtt%3Dcultivator&facetInfo= even with a slightly higher amp tiller. It’s worth the sweat to me to not have to worry about gasoline and small engine maintenance. I manage a relatively small total area, for a larger job you aren’t going to be using a little front tine guy like this whether electric or gas anyways 
Clay holds water and nitrogen much better than loam. Of the 3 main soil types (clay, loam, sand) clay is the most fertile. The problem encountered is the difficulty in getting good root growth in clay. While removing and replacing large amounts of soil may seem like a feasible way of doing things you are talking about thousands of pounds and cubic yards of material both in and out. Clay also infiltrates like crazy so if you dig a hole in clay and add a loam after it rains a few times you’ve got a loamy clay anyways. So the typical and easiest answer for clay soils is the mass importation of compost. Hence, a tiller!
Clay also tends to be alkaline and low in iron and trace elements but a bit of sulphur, ferrous sulfate, and seaweed extract fixes that up easily enough.
Gardening in clay soils also depends on how deep the clay is - central TX you just go down 16 to 20 inches and you’re at sandy limestone, drainage no longer a problem. Central OK and you’d better plan on using 6 inch raised beds and/or digging channels.
Use a shovel, heavy fork, or hand tiller (I linked one above) to break the clay into power tillable chunks while it’s damp, then power till your compost in when dry.
Once you’ve gone through amending your clay soil it’s pretty awesome to garden in. Takes a single season and some sweat to go from hard pack clay to the most productive garden soil type on earth. For those who have loam a 15%ish amendment of clay can radically improve the productivity of the garden for both ornamentals and edibles.
Anyways - sorry to write a book there, just wanted people to know you can in fact do some amazing gardening in clay
My dad loves his electric tiller. Uses it once a spring in an heavily amended clay soil in a typical San Jose backyard (small ~ 1/10 of an acre)
Be honest, you have cut at least one extension cord with your equipment at some point, right? I have personally hit 3 cords in my 30ish years of using electrical yard equipment, one was repairable. 
Cool, I have a similar San Jose back yard! Might actually get one of these if they’re still available once I have a chance to discuss it with the roommate/owner.
>40 years and never once.
I received mine today, only two days after ordering! Awesome service woot, thanks! Anyways, I took it out of the box, put it together (~10 min.) and put it to use on an 8’ x 10’ garden that wasn’t used this year. Ground was a little hard and the tiller bounced a little, but it eventually started breaking up the soil, and after an hour of work I had a nicely tilled patch of ground 6" deep. Power is sufficient for little jobs like mine, the handle is comfortable, and the unit is well balanced. It’ll lay down in the bed of a truck with the ballast tank off, and sturdy while upright.
Overall, I am very happy with this woot, probably my best woot, although the Microsoft wireless mouse woot was a good one. God I love my mouse.
Lightning fast shipping here too!
Ditto here as well!
I never received my tiller…Woot claimed the shipment was lost. UPS never received the package. I’m very disappointed. Now Woot claims they don’t have the tiller in stock and cannot send me one.
Whoa, that sucks. Hope they made it up to you.
I’m sorry. We do often sell until sold out which leaves us none to replace with. 