Re: Elcan Specter 1.5-6 questions
My sense is that the range you are interested in is ideal for the Elcan 1.5-6x. Then again, it depends on how precise you want to be. The reticle's red dot is 1.5 MOA at 6x, and is 6 MOA at 1.5x (ie SFP). You won't use the red dot past 200 yds as the optic runs on holdovers. Up close, the red dot with two eyes open works well for me. Some mount an additional MRD on top for the up close quick stuff. I tried this and it is fast, but it leaves the MRD very exposed to getting hammered.
You would need to figure out how your rifle and preferred load relate to the calibration of the reticle. I wouldn't count on being more precise than 2 MOA from 400 to 700 yds unless you invest in fine tuning your holdovers and have time to make the shot.
Some dislike the ARMS mounts; I've had no problems but have not subjected mine to intense field conditions. Also no problems returning to zero when remounting, and, no issues with a zero shift going from 1.5x to 6x. The levers mate fine to the POF rail, but there are some new adjustable levers on the market that allow you to adjust the tension if needed.
It's fat, mounts high on my POF, and needs an adjustable cheek piece.
Eye relief is 2.75", so BUIS may not fit behind it depending on your rail, LOP, lankiness of neck, etc.
The glass is extraordinarily clear, field of view is huge, exit pupil is 8mm.
For my purposes, the Elcan is uniquely effective. I can't say that it is a better solution than the SWFA as that depends on how, and what, you shoot.