I'm looking to improve the xB's handling. I was wondering if anyone could shed some insight on which way to go. I'm currently considering either an H-brace, possibly from Tanabe, or going with a rear sway bar kit. Any input would be appreciated, particularly those with first hand experience of said products.

 

This is about all you can do:

Strut bar
Front sway bar
Rear sway bar
Coilovers/Springs
Wider tires

Bam, there you go

 

You can replace the struts and shocks as well.

There's a lot of money in suspension. But there's also a lot of options. Have fun.

 

Cheapest way to go would be to add a rear sway bar and you can install it yourself. Don't add a front sway bar cause in my opinion they don't do crap.

 

Yes, the rear sway bar and springs are probably the best and cheapest start to any suspension job and it is very effective, you'll notice instantly.

after that go for the full shebang, coilovers on new shock/struts with bushings, camber, arm bars, dampers, you name it, it will help. autox here we come!

 

It also depends on your budget. Here's how I went about my xB suspension upgrades (in order):

-TRD lowering springs ($120),
-1/2" rear hub spacers ($50 ebay)
-TRD Rear Sway bar ($90 new ebay)
-Switched to 17x7 Volk wheels with 205/45/17 tires from stock 15 steelies 185/60/15 tires (~$1400)
-Switched to Tein S-tech Lowering springs 3 weeks ago ($150), TRD springs will be posted for sale soon.
-Switched to TRD Waydoo Sportivo Shocks/struts
-Energy Suspension front sway bar bushings ($22)
-TRD Strut Tower Bar ($60 used from another scion owner parting out)

I would recommend the rear sway bar and energy suspension bushing upgrades for immediate handling improvements. Then lowering springs/Shocks/struts.

 

GT Spec 4 point front chassis bar + 2 point mid chassis bar will also improve handling. I was lucky and won these items at a Scion Vip 2005 event.

 

I should have mentioned in my op, that the box is already fitted with KYB Echo struts up front, TRD struts out back, and DF210's all the way around. Also just recently did the front end link bushings, so we can knock those off the to do list.
Right now I don't have the funds for wheels/tires, and/or coilovers, but they are on the list. Hence why I am looking for a simple, and somewhat inexpensive suspension upgrade such as the rear sway bar, or "H" brace, and since they are remotely close in price I'm having a dilemma deciding which way to go. Thanks for the input so far.

 

If hotchkis makes a full spring/swaybar kit for the xb1 like the do for the xb2, I HIGHLY reccomend it. Along with a strut tower brace, it completely changed the cars handling characteristics in a good way .

 

The hotchkis kit is nice for the gen1 if you can install the front sway bar. You will need to drop the engine compartment in order to do so. The alternative to that is the Energy Suspension bushings.