I had a 327 and when it got to 3 years old I bought this one. As you say it's cheaper just to buy a new one rather than change the cells.
Not to keen on the Kane as it's quite bulky and takes ages to purge etc. I've got one that another guy uses and it's had to go back twice because it's thrown a wobbly. Credit to Kane though, they've turned it around in a couple of days and FOC both times, I just paid postage to send to them.
I've always used testo and they've never missed a beat, I use JMW to calibrate though, testo though plumb center is utter ****e.