McGizmo (Haiku) Owners: Which Battery Pack Do You Prefer?

A month or so ago I posted asking for help regarding a high-end torch purchase, and after much excellent advice from you all and some careful consideration, I think I've finally settled on going with a McGizmo, and probably the Haiku. That said, I'm stuck trying to decide on which battery pack I should go with, specifically whether to choose the 1x CR123 or the 1x AA pack. So the question is, for those of you who have had/currently own both, which is your preference, and why?

If it helps, my main criterion for choosing are:
1. Size (prefer less bulk in pocket);
2. Ability to run "stock" McGizmo LE's or Tana/DatiLED engines using either primaries or lithiums as applicable (i.e. which battery pack would be more suited to this task; I *think* a 14500 has enough juice to power the Tana/DatiLED engines but not positive)
3. In-hand comfort;
4. Grip possibilities (specifically cigar-style, I've heard the CR123 pack is great for this but not sure if it's possible or as comfortable with AA pack);
5. Clip retention vs. pocket shredding.

Thank you all in advance!

I've not owned the AA pack, however, I am inclined to say that the CR123a pack is more ideal for your criteria.

1. The CR123 is shorter and will have less bulk overall. The AA pack might be slightly slimmer though.
2. As long as you're using either 14500 or 16340, they both have the same voltage and will power aftermarket engines the same.
3. If you're using a full-handed grip then the AA will be more comfortable if you have larger hands.
4. Cigar-style will be more comfortable with the CR123. Weight will be biased towards the front using the AA pack which isn't ideal for the grip.
5. Clip retention should be the same between the two if they're running the stock McGizmo clip.

I had a good post here and then lost it due to a busy server. Grrrr

To summarize my point, I have both a AA Haiku with AA converter McG LE on Eneloops and a CR123 Haiku with DatiLed LE on 16340. I've mixed n matched a variety of McG heads and paks and LE over the years. I really do like the AA body. It's not a ton longer than the 123 but it's slimmer and fits very nicely in my hand and in a front pants pocket.

I like both and EDC both, had been carrying the AA for quite a while but currently the 123. The Haiku is the only light I'll EDC these days after many different sizes and varieties.
The AA pak with AA LE is the ultimate EDC in my opinion. AA batteries are common and varied, NiMH being a good main rechargable source with lithium primary a good back up or even a decent alkaline in a pinch or Li ion 14500 due to the voltage range of the driver.
The AA pak is very slim and sits great in the pocket, I always use the pocket clip.
Then there's the 123 pak, much better for cigar grip as you've asked for and also my choice for the 3S/Hive/other maker LE's running a decent Li ion (or even Lifepo and lithium primary CR123 as back up and 2xAA in the appropriate pak for Mcgizmo LE's). I'm prone to Mcgizmo LE's due to their voltage range (you won't be able to run 3V batteries with Tana or datiLED LE's for example as you know).
A lot of people seem to like running 14500 in AA paks for the higher voltage heads (which limits you to one power source) but for me the AA pak is for the AA LE.
Regarding clip tension, it's awesome and is what keeps your light secure. It can be easily adjusted particularly if you have a Thorp driver in the event that you need to take the clip off for tuning. I like my clips firm as they come from Don but you can bend them out a bit until it eases off although be careful to not go too far as then you'll need to remove the clip and put it back on pointing the wrong direction to push it back down then re attach the right way.
Hand comfort, they're both great but in different ways. The AA as you noted is very comfortable but then there's the cigar grip of the 123. I've got the AA, 2xAA and 123 paks on Haikus and I like them all in different ways but I'd recommend the 123 pak from what I'm gathering.
I'll add that Theodore and nbp have summarised well in the above posts.

Maybe to be different, I guess, my vote for "best" McClickie-Pak goes to 2xCR123A (16650)

I think it complements the design aesthetic of the Haiku better than any of the others.

It also provides a different and potentially more useful voltage range for power (especially of non-stock light engines)

And I find it easier to secure with a sturdy grip.

I agree with F89, AA pak is perfect! Still has the grip like 2x123 pak and in smaller package.

I like the standard CR123 pack for pocket carry, however with my Makai head, I use the 2 AA pack. I am going to order a single AA pack and try that out. Also, I really like how the Mule head looks on the single AA pack.