Well, you need to balance the inconvenience of LGW with the ease of LCY...certainly on the new domestic route LCY-GLA (which is the one I'm most familar with) I've not yet been on a full plane or had to sit next to anyone. But yes, it can be pretty tight in there and for someone over 6' (unlike me!) I guess it could be unpleasant. BUT - fast check in, fast baggage reclaim, fast, cheap links into central London, no endless wandering down long corridors, smaller planes so you get on and off more quickly...that more than compensates for me, but admittedly only on a shortish flight. MAD might be more of a toss-up between LCY and LGW I suppose.