Bug

There is currently a bug where Xaku guns will not target enemies that are in a ragdoll state
https://www.reddit.com/r/Warframe/comments/1au25kz/xaku_guns_no_longer_attack_enemies_that_are/

Archon Update:

I was lucky enough to get a Tauforged Crimson Shard so I added 15% Strength and swapped [Power Drift] for [Cunning Drift]. Since clearly Range is so strong that DE didn't add it to any shard options means this is definitely worth investing more into. :D

Using just 1 of these shards basically puts us back to what we originally had, meaning we now have 4 more open shard slots to fill. Currently the other open slots were used for Duration until I get more Tauforged.

I have seen some builds utilizing Molt Augmented arcane and this could potentially be an option. However since I don't have these and it requires getting 250 kills in order to get the 60% bonus strength from it. Its hard for me to recommend it currently. If that was a valid option then you could remove [Blind Rage] for something like [Vampiric Grasp] and dump your shards into a mix of strength and duration.

Notes:

I find it unnecessary to run Corrosive Projection since your Gaze can strip 100% armor/shields once you have 200% power strength.

Having more range not only helps with Grasp of Lohk in grabbing (~39m) (~42m) but also the range at which your guns will target enemies (~21m) (~22m). This also helps with 3rd (larger AoE) and 4th abilities (larger blast radius to proc more Void weakness)

Acanes are personal preference. But energize is fairly mandatory to upkeep energy. Guardian was the only other good Arcane I have.

Optional Helminths:

Spectrorage - replace 3rd ability and use Spectrosiphon; mainly against infested where gaze is unnecessary.
Pull - replace 1st ability and use Greedy Pull; mainly used for loot farming.
Roar - replace 1st ability; useful for more team-based scenarios and boosting gun damage.
Resonator - replace 1st ability; useful for defensive missions and more crowd controlling.
Gloom - did a bit of testing and didn't feel like this synergized well with Xaku. Either have to dump range or it consumes to much energy.
Breach Surge - untested
Blood Alter - untested

Final Thoughts

as you can see [Xaku] has tons of potential depending on what you like or want to use them for. If you are staying with the original setup I will say its fairly mod tight meaning there isn't alot of room for change. Because 200% strength is mandatory for armor/shield stripping as you can't stack two Gazes on top of each other. Also having a good amount of range is somewhat mandatory as this helps with overall aura of stripping + granting you more guns which means more damage.