For me personally, Ativan(Lorazepam) has alwys seemed an ideal benzo for tapering. A LOT of people will disagree with me though, but, for me personally, lorazepam is a very neutral, almost "bland" benzodiazepine, that has a good duration of action, yet only a moderate half-life of 10-20 hours. Compared to diazepam, it lasts longer, yet has a shorter(and far less variable) half-life.
It also ha a very slow onset, similar to clonazepam, except that the initial onset is even slower, though the peak effect occurs about the same time.
And it's medium potency; I mean, it's fairly potent by weight,(1mg lorazepam= 0.5mg alprazolam, 5-10mg diazepam, or 0.25*-0.5mg clono(chronic-acute)).
And it doesn't accumulate, yet two doses a day will generally hold you. But most p all, for me, and practically everyone I know IRL, lorazepam simply has no euphoria, whatsoever. Alprazolam is pretty relaxing and euphoric, and even diazepam can bring some euphoria with it's very fast onset; yet lorazepam just has such a slow onset, and it doesn't pack the unique punch of clonazepam(not to mention it doesn't infinitely build up, making it easy to abuse, suprisingly.)
If it wasn't for it's fairly good duration,(anywhere, 4-12 hours) and th fact that it actually is an effective benzodiazepine, in regards to the "core" benzo effects(anxiolysis, sedative, and of course it completely covers benzo WD) I wouldn't like it at all, but, it's these very properties that could make it a good benzo to taper from;
We seem to have similar idea's about benzo's, and lorazepam to me is very neutral, in nearly all aspects.
But, some people think it's horrible for tapering, and you can find their reasoning for yourself. A lot of people look at the half-life, but with diazepam, half-life is practically useless, it just builds up in fat tissue, like u said. I've even herd doctors claim to someone I know (while handing them a script for 15mg of clonazepam at an ER) "Oh, I would never write Ativan, it is much more abusable than clonazepam" I was like WTF?
I do know the logic behind shorter T1/2=harder WD, but the point is, you're not supposed to WD, but taper. I certainly wouldn't recommend switching to lorazepam and running out.
More people have traditionally has success with Valium, though, I'm just offering my thoughts with an alternative.
(Oh, and on last advantage of lorazepam; it is NOT metabolized by the P450 system. Obviously, this reduces drug-drug interactions, but, perhaps more importantly, it has a more consistent profile, with less individual variability in it's metabolism.)