Thanks for an interesting idea.
Things not to like include the huge bid/offer spread, as implied by the illiquidity highlighted in Oliver's article. Also, the shares have improved a lot in price of late, leaving less upside for late arrivals. Not to mention volatility, which leaves an investment here vulnerable to correction, should unforeseen developments occur. There is no getting away from individual stock risk here and unlike with bonds, no promise of an escape route on redemption on a fixed date some way down the road.
Nonetheless, floating rate note instruments such as this are as rare as hens' teeth so far as the retail investor is concerned. Oliver is suggesting that interest rates can only rise from here and how can one argue?
As somewhere to park some cash for the medium to longer term - as a means of protecting a small proportion of capital in a widely invested portfolio - I can see that this idea makes sense.