So my wife put out fresh Bird Seed in the back yard and I setup my A73 with my Sigma 100-400 glass on it and waited. Once the birds started showing up it didn't take long for me to get a serious GAS attack! My tripod with a Ball Head on it absolutely sucked. The first thing I did was to order a Manfrotto XPRO 3-way Pan & Tilt Head. I'm sure that you experienced types have seen that no matter how many customer ratings give the product in question GLOWING PRAISE, another guy is going to come along and state that that product is a streaming pile of poo! Next I began to look at Tripods. I had no idea how expensive a tripod can be. Anyway, I have narrowed my choice down the Manfrotto 190XPRO Aluminum 3 section tripod.....or should I get the 4 section model of the same thing? There's nothing easy, is there. So, why would Manfrotto sell both a 3 section and a 4 section tripod that is exactly the same otherwise? Anyone? While you're at it, you might as well give me your recommendations for tripods. Thank you Ladies & Gentlemen.