Mass Effect 1 - Stasis Question

I checked some of my ME1 Sentinel and Adept Shepards. I do not keep a lot of saves around, so I can only really check it out at the final boss (frog Saren). Most of my Sentinels and Adepts appear to only have Basic (1-point) Stasis. The first Shepard I had that used Master Stasis was a Sentinel, but frog Saren is completely immune to Stasis.

So apologies if I do not know if Advanced Stasis would work on some other enemies. Like I said, I do not keep a lot of saves. I generally only keep one save per playthrough that I constantly overwrite; occasionally I may keep a few more saves, depending on what I am doing in the playthrough.

But generally, I would recommend only ever keep Stasis at 1 point (Basic Stasis). Stasis can only ever affect 1 enemy, while Lift, Singularity, and Throw can affect multiple enemies. (Note for Lift, you may have to aim at the floor to get the radius to work; hopefully this will be fixed in the Legendary Edition.) On higher difficulties -- and some enemies -- you are not going to get the full duration out of your Stasis or other Biotic/Tech powers, and some enemies seem to be immune to Basic versions of powers like you point out. Basic Stasis is good for the occasional enemy you want to lock down. For Sentinel and Adept with the Bastion specialization (can harm enemies in Stasis), with Master Marksman (Pistols) or a good assault rifle, Basic Stasis will give you enough time to kill the enemy held in Stasis.

This is not to say that Advanced or Master Stasis is a waste. Advanced and Master skills are better than Basic skills, obviously. I just think you are better off putting your points into your other abilities since they will be more useful to you overall.