I don't get the Hunter mode speed&vision obsession, imho is not always useful as people make it to be.
If you use a flamer build imho is better to have extra damage as the 15m of HM range matches the max flamer distance, plus both your weapon AND flamer benefit from it, if you use some long distance weapon you don't really need extra speed or vision, and if you use a geth weapon (or a weapon with defense multipliers) you gain more from the geth multiplier (or defense multiplier) if you take damage, and besides GPS, GPSMG and Javelin can be used at mid/long range.
Speed and vision is useful when you play at close/medium range or with a weapon with speed movement/fire movement penalty (ie. Spitfire/Revenant), OR if you want to abuse the wallhax with some setup (ie. crusader with drill rounds).
Moreover, if someone wants to play the GT as a flamerless weapon platform imho taking speed and damage without thinking first if you REALLY need it is a big mistake, GT has not a great weapon output by himself, if you cut even 10% (expecially if you use geth weapons/weapons with defence multipliers) the advantages start to wear really thin, and again, it's not like is impossible to play with "only" 10% more speed and 15m wallhax...
Just to make it clear, out of the 3 geth characters with HM I use speed and vision on 2 of them (GE with Wraith, GI with Piranha/Hurricane), so I'm not saying the rank 6a sucks.