I've seen it - mentioned it in the Classic Who watch thread.
It's nice to have another episode back in the archives but it's a decent episode rather than outstanding. It's a pretty simple story which is well directed, with nice performances from the regulars & Stephanie Bidmead.
I suppose the problem is there is just not much to this story - if we had all 4 episodes then it would probably get a bit ignored like Planet Of The Giants or The Sensorites. Having it back is probably the most interesting thing about it.