I'm about to purchase this:

Sachtler | DV-12SB ENG Carbon Fiber Tripod System | 1263 | B&H (http://www.bhphotovideo.com/c/product/382500-REG/Sachtler_1263_DV_12SB_ENG_Carbon_Fiber.html)


88 pound capacity legs. I don't anticepate ever going above 25 or so pounds with my EX3 + add ons.

Given that I will never go beyond 25 pounds would there be any reason to ugrade the legs to this:

Sachtler | CF-100ENG HD 2CF Carbon Fiber HD Tripod Legs | 5390 (http://www.bhphotovideo.com/c/product/78761-REG/Sachtler_5390_CF_100ENG_HD_2CF_Carbon.html)

Will I be gaining anything stability wise with by going with these heavy duty legs given the max load I anticepate? Or would that just be crazy overkill here.

The title of your post says it all, and, all things being equal, is very true.

The rigidity of the second unit will be a quantum leap over that of the first, with the inevitable trade off of extra weight.

At 10.8 pounds (including the mid level spreader - sold seperately) without a head, it's getting up there for lugability, but if you can afford the extra dosh and the inevitable hernia, go for it for that extra rigidity.

One things for sure, it won't matter what camera you park on it for the next 10 years plus, it will still be doing the business when the slighter unit will have fallen by the wayside.


CS

I wonder if it's always true though.

For instance, is there a common standard for measuring weight capacity, or is this a marketing number? Also, how much a tripod can hold is only loosely coupled with how much it will twist.

You might find a high number from a bottom tier manufacturer and a low number from a top builder, and the name brand tripod might just be the better performer.

So, yeah, capacity is good to consider, but I'd only give it so much weight (a pun!).