We haven't tried the SMA staydown but my LO is on Enfamil AR which I think is a similar kind of thing. We find the enfamil fantastic, really stopped the possetting and suited him much better than the cow & gate comfort he was on.
I did look at the staydown at one stage and if I remember right the mixing instructions were the same as the enfamil. You need to add the powder to cold water and roll it between your hands before you shake or it clogs the teats and doesn't mix properly. These formulas have added ingredients like rice starch which make them thicken so they can cause constipation. Some formulas are thicker in the bottle, some like emfamil are a little thicker but actually thicken in the stomach when they hit the acid, not sure which way the SMA works. Either way you will probably need a faster flow teat.
I wouls give it a go, you can always switch back if it doesn't suit. Are you UK? If so Enfamil AR is available on prescription so it may be worth speaking to your Dr or paed about it or other reflux formulas.
HTH!
Laura
