[NLRS] Dual Band Radio to Seperate Yagi's

[KB0NLY]

Looking for some more opinions on this.  Here is the situation, I'm going to run a 4el 2m and a 6el 70cm beam to my FT-8800 for FM use, want to be able to switch from the vertical for a little more gain sometimes, some say use a diplexer to split them, some say use a "T" and it will be fine.  I see Cushcraft's dual band yagi's use a "T" and a harness, is that harness cut to any specific lengths or is it just relying on the resonance of the antenna's?

Pro's/Con's of using a diplexer versus a "T", and vice versa?

73,

Scott KB0NLY