Too Many Lenses...

Among my Christmas gifts, I received gift certificates towards some additional camera gear (it is for Adorama).  With this money, I plan on picking up a new lens.  The gift money would cover all of some of the options and leave me a bit short on some of them.  However, if I have to kick in a bit extra to get what I decide is the 'right' choice, it's well worth it (and much cheaper than if I had to pay for the whole thing).

I had a few lenses on my Christmas list already (we have a big shared Google Docs spreadsheet for the whole family), only some of which are even remotely realistic; I don't expect anyone to actually get me the Canon EF 70-200mm f/2.8L IS II USM:

The other lenses I looked at are not cheap, but are a good bit less expensive, like the the Canon EF 100mm 2.8L IS USM Macro:

...or the Tamron 18-270mm f/3.5-6.3 Di-II VC PZD:

The rationale:

• The 70-200 is a very versatile focal length and the above is a fabulous lens that I'd love to own at some point.  I rented (much cheaper, much ligher) the f/4 IS version for our trip to the UK this August from LensRentals.  I borrowed Matt's original version of the 70-200 2.8 IS for our honeymoon.
• I do not own a macro lens yet, and am interested in macro work.  The IS present in the L version is supposed to be stellar, and it seems like it would make handheld shooting much more feasible; it would be nice to avoid having to relegate macro shots almost entirely to the tripod.
• The Tamron was picked just to serve as a do-it-all travel lens.  It could work for trips on which I don't have the space to pack a few lenses, or if were were out on a day trip without any foreknowledge of what I'd be shooting.

Santa did not bring any lenses (although he did bring some nice photography accessories, like a Vello ShutterBoss and a pan/tilt head for my tripod), but he did bring these gift cards to use for photography equipment.  I thought about the macro lens (as well as its 100mm non-IS, non-L little brother) and the Tamron, and the more I looked...the more I decided to nix the Tamron from contention.  It seems that (aside from a few "this lens does EVERYTHING!" user reviews) most of the detailed reviews of this lens characterize it as of middling build/durability and good but not great optically.  I think the LensRentals commentary best summarized it as a 'compromise lens', and that is probably to be expected in a not-very-expensive super (15x) zoom targeted at crop sensor cameras (of which my 7D is one, admittedly).  I may actually end up using it, but I think I'd feel like I was 'being lazy' if I left it on, as opposed to bringing 2 or 3 better-performing lenses.

Somewhere in all of this, I had another thought: what about an ultra-wide?  I have really liked landscape photography on our trips, and such lenses are also great for architectural photos during these trips.  This complicates the decision greatly, as research suggests 3 contenders:

#1: The Canon EF-S 10-22mm f/3.5-4.5 USM.  This lens seems to be universally well-reviewed, and seems a bit like my existing 17-55 2.8: L optics/internal construction without an L physical exterior build (or designation); I'm not sure Canon would ever label an EF-S lens an L, in any case.

#2: The Tokina 11-16mm f/2.8 ATX Pro DX. A tad less wide than the Canon, but with a constant 2.8 aperture.  A full stop better in the best case, with a gap that only grows from there.  For landscape photography, the speed is likely irrelevant, but it might be useful for architectural work.  The reviews also suggest this thing is built like a tank: optics on par with (some say better) than the 10-22, but with a build more like a Canon L.  Its zoom range is so small that it almost feels like buying a prime.

#3: The Sigma 8-16mm f/4.5-5.6 DC HSM.  I believe this is the widest rectilinear lens available for crop sensor cameras.  It has a bulbous front element (and a fixed hood), so conventional filters aren't usable.  This is the slowest, but also the widest.

So....it comes down to 2 decisions, in this order:

1. Macro, or ultra wide zoom.  My existing 17-55 is pretty useful for wide shots as it is...but these options are a lot wider yet.  The Canon macro could be used if I moved to full frame one day, whereas all of these ultra wides would only ever pair with crop sensor cameras like my 7D.  I'd probably take more shots/would get more use out of an ultra wide than a macro.
2. If ultra wide, which?  I think it's really between the Canon and the Tokina.  The 2.8 is attractive, but reviews suggest it's pretty soft at 2.8, and so the aperture advantage is really so great.  I have never owned a third party lens, and so also wonder (and see this mentioned in some user reviews) about AF behavior for such lenses versus the genuine Canon.  Ken Rockwell raves about the 10-22.  Then again, he is sweet on the Tokina, too.  I'd welcome any input!

I'm not sure which route I'll go.  I am tempted to rent both the Tokina and the Canon ultra wide lenses from LensRentals for a weekend and take a ton of similar shots...and then see if I have any preference for the results after getting them loaded into (and lens corrected) in Lightroom 3.  As for the macro, I could rent that  as well, picking a different weekend to play around with that.