While my wife thanks you, I must admit to being a little disappointed. I personally feel the lag issue has been overstated, at least in terms of success rates. My own personal experiences are that I have successfully managed to acquire +5 tomes on all 5 of my toons. Lag seems worst when there is large number of people online, noticeably on the first day or two or around midnight GMT. I imagine this is when most of the north american users are playing. As a basic rule if the time between openings decreases you can bet that the lag increases.
The best way I've found to avoid the lag (and probable failure thereafter) has been to play the lower level toons at that time. Possibly because there are less persistent spell effects lingering, which again is probably simply less load on the server.
All in all, I'd say my success rate has been around 80%, and that most of the failures were on the first day or so or during peak usage. As much as it may be nice to think it's all because of my skill, in reality I believe it should be achievable by others if they plan carefully and also have low level toons to run (a big if of course!). If however you don't I'd suggest the best bet is to try and find a low peak time for the run, again of course not possible for everyone. Failing that simply wrestle with the lag and hope for the best
I must admit I simply don't understand why people are glad it's been taken down though, surely simply not attending Mabar gives you the same experience? In fact the lag would probably keep decreasing for the rest of us ... win win I would have thought.
Personally I have sympathy for the devs, trying to accurately replicate and test load on this scale must not be easy.
All the best to everyone with your final runs regardless