Dennis,
the comparative figures refer to 5-year performance (not 1-year), but you are right: the IT has done significantly better than the similar UT, and even taking into account HL's dealing charges for shares within an ISA, the IT would be a better bet, certainly over a 5 to 6-year period. However, the IT is trading at a negligible discount at present so, though I hold some of each, I have topped up my holdings of the UT which, in the last month or so has actually done a tad better than the IT.
My advice was based on the assunmption that Red Man, as a novice investor with a small amount to invest, would find UTs less intimidating than an IT, despite my general preference for ITs over UTs.