Some tips for the Old Man Missions and anyone wanting that version of the orb (A lot more practical since it is a click rather than a proc). I haven't done these in over a year now so my apologies if I'm off on any specifics.
There is a 3 minimum player requirement for the mission. There is also a level 80 requirement for the averaged out level of the whole group. The requirements for winning are to simply traverse each instance killing the required old school named of each zone. Death in the instance is just an inconvenience of re-entering the instance and recovering. There are three different instances that each have their own lockout: Nagafen's Lair, Undead side of Lower Guk, Live side of Lower guk.
I would personally rank the Nagafen's mission as the more challenging of the three. Undead guk seems a tad easier overall depending on class(es) doing the mission, but one notable quirk with the live side mission is that (if nothing has changed) the faction the live frogs use seems to be based off your true toon's faction standing and not the shrouds. This can make things much faster/easier if your faction is high enough (warmly iirc?) that you will still not be KOS by the end of the mission. In that scenario the enchanter's memblur can remove some necessity for even using mez in certain situations.
I'm sure some of this may be personal preference, but if you can play the Enchanter well for these missions you'll have a much easier time thanks to the pulling/crowd control/buff capabilities. Necromancers are really strong as well in these and may be the prime choice if you want to attempt soloing the undead guk mission. I did these quite a lot for the sake of some augs, and solo'd undead guk on the necro shroud once, and boxed both guks a few times.
With that said, it was much much easier when I got one person to tag along and play a third groupmember while I boxed two. With that group setup death was never really an issue and I could zip through all the missions without breaking a sweat.
No matter the strategy or set up, make a point of using those shrouds to all the potential you can to make it really easy. They are practically carbon copies of a level 50 toon of the same class so figure out which spells you'll need in which situations.
I know my post is getting lengthy and going all over the place, but for a final point I should touch on the spells, as that is counter intuitive to what you would see on a real toon.
All of each class' spells are accessed through the AA window rather than a spellbook, if you don't have exact memories of spells for that level range it can be confusing at first figuring out which spells are the best versions to use. I recommend using allakh's spell page to see which are your best option for the class. The one advantage of it working this way is that you aren't really limited to only having a spellbar's worth of stuff at your disposal.
Edited, Jan 17th 2012 12:09am by Saeel
Edited, Jan 17th 2012 7:53am by Saeel