Bottom line: Replacing stock CRX 9005 (high beam) and 9006 (low beam) bulbs with HIR1 (high beam) and HIR2 (low beam) bulbs really does give you a major improvement in your ability to see at night (I find this especially true on unlit rural highways), while maintaining the stock CRX headlight aiming/cutoff! i.e. the HIR bulbs don't change were you are putting the light (so if your lights are aimed well, the normal CRX light cutoff should keep your low beams from blinding oncoming drivers with light glare), but the area that is lit will be much brighter than with the "stock" bulbs.

NOTE: The high beams on a CRX will clearly put glare in oncoming driver's eyes, and this is even more true if/when you upgrade them to extra-bright HIR bulbs. However, since you really should only be using your "brights" when you don't have other traffic around (and otherwise "dim your lights"), I really don't see where brights "glaring" a bit more than stock is much of an issue (as other drivers shouldn't be around to care, or you shouldn't have your high beams on anyway). And I must admit that on the few times (with no other cars on the road) when I've turned on my brights (which since the CRX seems to come stock with "quad" high beams, means that both the HIR2 lows and the HIR1 highs are on when I ask for my "brights"), I find that virtually the entire road seems to be lit up. Of course, since even "just" the low beams do a very good job of lighting up the road, I expect I'll use my "high beams" even less than I used to before the HIR bulb upgrade (but it's still nice to have them around for those "just in case" situations where you may need extra light to avoid some road hazard).

NOTE: There are apparently a handful of places you can buy genuine Toshiba HIR bulbs from (along with a number of sellers pushing cheap knock-offs of HIR bulbs, so be sure to verify your bulb source carefully). However, FWIW the seller I ended up going with was "CandlePower Inc." (which sold me the bulbs for $23.95/bulb + around $10 shipping for the order)::
http://store.candlepower.com/hirlighting.html

And while (unlike some other vendors) they didn't pre-mark the bulbs (as to where you need to trim the tab) it was none-the-less pretty easy to hold up the HIR bulb to the existing bulb to see where you needed to trim. The main (two) cautions I would give about the process are:

1) Like all halogen bulbs (and HIR bulbs are just super-efficient halogen bulbs), do NOT let your fingers touch the bulb itself if you can at all help it (i.e. work from the base of the bulb). If you absolutely can't help touching the bulb, use a clean cloth to do so (vs just your hands), and carefully wipe off (with a clean cloth) any prints you do accidentally get on the "bulb" itself. The reason this is so critical, is that oils from your hands can actually effect the heat layout of the clear quartz globe of the bulb, thereby causing it to weaken and fail quicker than normal. So just keep your fingers away from the "bulb" itself, and handle it by the plastic bulb base.

and 2) Be extra careful to make sure you are holding both the original bulb (which you are using as a template) and the HIR bulb (which you are trimming the top tab of to make it fit) in exactly the same orientation. i.e. it is all too easy to have the original bulb (which you are using as a "template") pointing one way and the HIR bulb (which you are trimming the top "tab" of) facing the opposite direction. And if you do this without catching yourself, than you could easily trim the opposite side of the tab from what you need to trim (thankfully I caught myself about this issue, before doing the actual tab trimming)!

NOTE: Virtually any tool (dremel tool, "hot knife", or even toe nail clippers) that lets you cut plastic (without making a mess) will let you do the trimming needed.

In my case, I did the low beam (HIR2/9012) bulbs first, and actually used a toenail trimmer (because that is what I had available at the time). I will say that it worked, but it was a little tedious, as you had to be careful to "whittle away at it" by "clipping" small chunks around the edges. Because if/when I tried to make a "too big bite" the toe nail clipper would get "stuck", and I would have to back off (or risk a real mess if/when things didn't split neatly). So if you want to use a toe nail clipper (not the smaller fingernail clipper, a full sized toe nail clipper), be a little patient, and try not to bite off more than small (around 1mm or less) bites at a time.

Of course, by the time I got around to putting my high beams (HIR1/9011) bulbs in, I had already purchased an off brand "dremel tool" clone. And, as others have observed, a small grinding disk on any sort of dremel tool seems to work very well to remove (gring down) parts of a HIR bulb tab, to make the bulb fit the stock CRX light socket. In fact, I found that my "dremel tool" actually did a much smoother/neater job (on my high beam bulbs) than my 1st attempt with a toe nail clipper did on my low beam bulbs. But even so, the toe nail clipper was still "neat enough" to do the job so that it was functional (i.e. so that the HIR bulbs fit nicely in the stock CRX bulb positions).

NOTE: Apparently, if you are willing to do even more bulb modifications (i.e. not only modify the top tab, but also modify lower "channel"), you can actually put the HIR1/9011 bulb in the LOW beam socket of the CRX, giving you even brighter "low beams" than I got with my HIR2/9012 bulbs for the low beams (I did go with HIR1/9011 bulbs for the high beams though). However, it seemed to me that the HIR2 bulbs were already extremely bright compared to stock bulbs (my new HIR2 low beams seem to give me an OK view of the road for close to a full city block), so I didn't see any point to making them brighter still (by using the HIR1 in my low beams). And the HIR1 bulb (since it's designed to be a "high beam" bulb) does use a little more power than both the HIR2 bulb and the stock 9006 "low beam" bulb do (which does effect fuel economy a small amount, due to extra alternator drag on the engine). And finally, the HIR1 bulb (again because it is designed more as a "high beam" bulb) only has an expected bulb lifetime about 1/3 as long as the HIR2's (almost stock) expected bulb lighttime. Which is why I decided to go with the HIR2 for the low beams, but did go with the brighter (but higher wattage and shorter lasting) HIR1 for the high beams. As a result, both my low and high beams are still stock wattage, but they clearly are no longer stock light levels...