FTL - makes sense for non-homogene grps?

[Ken]

In no cases is ftl ever ''required''.

It's just awesome to not have to make those 20ish macros to switch focus.

You don't need 20ish macros if you use modifiers to switch focus.
For example: "+" for set focus (with modifiers to determine which char you want) and "-" for clearfocus (of current screen's character only, so this key shouldnt be broadcasted)

However, if you want flexible group setups with FTL, you'll need multiple macros anyway.
I personally use focus and have stuff like:

"Focus account 1" macro:
/focus [target=SomeCharOnAccount1,exists] [target=OtherCharOnAccount1,exists]
/assist

This basically just checks to see which character is online on account 1 and selects that as focus whenever I switch to that window.
So yes, I have 4 focus macros per account, but on the other hand I don't need to create extra macros if I create new groups. That means that if you have many groups, you actually save macro space by chosing a focus-based system rather than an FTL-based system.

As with most macro systems, each has its own benefits and drawbacks.