What are the currently 'best' stalker primaries and secondaries?

I have been thinking about trying out /ice also.
Can you give a basic comparison vs /ninj (nothing fancy with a lot of #s)?

Sure.
Nin offers the completely rounded protection of softcap defenses plus a heal. It has some good protection from all damage types in one way or another. It also offers a smidge of extra damage and mitigation from caltrops and blinding powder. I usually consider it the best pairing with electric because it easily allows the free AS talked about in my guide.

Ice does not offer the same generic protections all around, but at the same time the protection it does offer can be much stronger and more varied. It offers capped defense to only s/l/e/n. This at first seems a raw deal, until you realize how much stronger s/l defense is than any other type, as s/l accompany the vast majority of attacks. Ice gets capped cold resistance and a modest amount of fire resistance to make up for its lack of defense there. It still has a hole to psi damage and its HP boost is largely ineffective, but it has some other interesting things. It has a -dam/slow aura that will stack with defenses to further increase your survival. It has a pbaoe sapping power that can push you closer to the isoftcap, as well as effectively drain foes if slotted right (drained foes don't attack and few resist this). Then comes icy bastion, the jewel of the set, delivering significant chunks of resistance to all damage but psy, and increasing your regen and recovery significantly. All the varied forms of mitigation can combine to make one seriously tough character.

Best thing about Icy Bastion is it recharges so fast and has zero penalties. This is the first stalker armor set I've played that allows me to scrapperlock ("stalkerlock" just sounds dumb). The only thing about the set I find annoying is the graphic, I wish they had a zero FX option on all armor sets.

The recharge of it is both good and bad. It's bad in that, on high recharge builds, it actually has lower possible uptime than other tier 9's. The recharge is good in that it's available when you need it.

Micro, thanks a lot for the great insights. I have only run a couple of Stalker secondaries (Nin and WP) and this gives me idea of how to play with /Ice in Mids.

Thank you again for taking the time to respond.

I would say it performs "ok" (except for Hoarfrost) until 35 simply because its first shield will cover most damage by itself. It relies mostly on that and chilling embrace for a looong time. It starts ramping up from 35 to become somewhere between good and beastly. When they port this set to scrappers it will dethrone /electric as my favorite.

Defense numbers or mitigation ability? And specifically ranged defense? If you mean pure defense, nin and Sr can get range softcap easily, ea will cover most stuff, and ice will cover a little less without significant f/c defense.