One nice thing about HG is the (item-level, so doesn't protect from some endgame mob aggravations) petrification immunity. Although this is nowhere near as useful and important as levitation (across different runs), it could be used in defense of picking HG over Atomie (or brownie for that matter). I know at this point you're probably quite tired of re-doing your toon to suit forumposter suggestions but honestly KC's point about BUR reinc value is a good one. I would have suggested HG from the start if I was thinking you had it Luckily it's a great across-the-board BUR, which can make a pretty good "just about anything" (altho for non-tanks, half-elf is kinda weak usually).
Anyway, my point is that lacking levi is lame, but other than endgame application of levitation as a defense from toss deaths (malebranche, nabassu etc), for LL runs, the main runs you need levi for, as any toon expecting to soak a few hits (tank or even a caster that doesn't play like an uber GV ninja), you also need stone imm for (desert/db mainly, although uro does have 1 the glacial flow, but stone problems tend to be generally a lot less noticeable here). So, just pointing out that using HG actually doesn't mean much of a tradeoff for lowbie LL grinding/run progression in terms of "needed survival thingy that eats up precious gear slot".
Well, my Atomie sorc was only level 2, so I decided to start again with Half-Guardinal. I am missing my wings, and not used to a large toon, but I will keep her going, and reach 21, so I can upgrade her when I can find a better BUR book. Although I would love a Radiance Genasi book, I am more hoping to find a Half-Celestial book. That book has everything I need. Good charisma and feats for a sorc, wings, spell resistance, levitation, and it works with any race. I can have a sorc that is almost as good as Rad Gen, and I will have a fun time playing it. Plus, I can use Half-Celestial for making a cleric and druid. I wish I could trade for that book, but all I have to offer is about a billion gold, and a beaker I have on my bard, but have not activated yet. Oh well, I can always hope I get lucky.