Entirely different speakers - in fact you are unlikely to find two different speakers anywhere.
Magico is of the accuracy detail type and, to some like me, can come across as perhaps a bit brittle, dry and uninvolving, but due to the very low resonance fast, very uncolored, and articulate. The Tannoy is full, rich, involving, and musical but with not the articulation and detail of the Magico.
I actually wouldn't get either - I would try for a speaker that combined the strengths of both - such as Rockports, Ridge St Audio Sason, or Lenehan ML2 Limited (I have a pair of those on the way) - but that's me. I was at a recent meet where some speakers similar to the Tannoy were and while I liked them the guys there were going ga ga over them. Many there have heard my speakers which are more along the line of Rockports etc, and I thought mine were definitely better, but all except one other (he also owned my speakers) much preferred the speakers at the meet.
Its a personal preference thing - listen to both and decide what floats your boat. Of the two I would go for the Tannoy - the Magico's are a little brittle for me.
Thanks
Bill