I would echo most of Glyn's assessment of the Reaver: better option than a warlord because of the points cost, but rarer than warhounds. Think of it this way: if you're thinking of taking a leman russ coy., a reaver is also an option as it's the same points, but has voids, is fearless, has better initiative, etc.
As for the aesthetics, I greatly prefer the luscious-pattern, which the current version of the warlord is - if you like the look of that pattern AND want all your titan to 'fit' together, I would recommend getting the FW reaver. It has it's faults, but I like the FW model much better than the SG one. However, if you don't care, or like the mars pattern better, it's probably easier to find an old warlord and mars-pattern warhounds than reliably find luscious pattern warhounds. If you decide on FW, definitely call them, as the default email answer to "do you have warhounds" seems to be "no", and when folks call they oftentimes have some laying around somewhere.
EDIT: and no matter what Dwarf Supreme says, he LOVES the luscious pattern. it's his favorite. I think he took a hammer to his mars pattern titans a few days ago when he saw the light
