Now that the majority of our 40k armies are at a decent level, we've started looking at the Specialist Games, narrowing our choices down to Mordheim and Necromunda. In terms of fun and gameplay balance, how would you compare the two? I've heard that Mordheim has some real balance issues, but haven't really heard that about Necromunda.
Well, I can't say you'll get an unbiased answer from me, but I'll try to be balanced. As to gameplay balance, both have their issues. For me personally, Necromunda has less, but not by much. Both have gangs/warbands that can be more powerful than others, and ones that can be less. I personally find, with the exception of Van Saars and modern Redemptionists, that Necromunda is pretty well balanced with regards to the factions used, and with the nature of the game, there is a fair bit of equality in both games as to how things can turn out.
Ultimately though in selecting which game to play, I think your best bet is to find what suits your group the best. If you've found a group that already runs SGs, the decision will probably be made for you. Otherwise, I'd look into what you need. What makes or breaks either game is terrain. I'd figure out whether it's easier for you to make a futuristic industrial multiplex, or a sprawling fantasy city. I'd also check what miniatures you can get, and also what factions you and your friends are likely to play. The prospect of a good modelling project, or a tough battle to get good terrain may make or break it for you.
Both games have a sparse, but loyal fanbase. The Mordheim fanbase seems to be more active, but you'll be able to find rules and things on the internet that support either game. SGs are games where balance is difficult (but then it's hardly the opposite for the cores either), but I find the games to be better balanced in how the core system supports itself, and as it's consistent it is possible for individual groups to fix issues with House Rules and so forth. Whichever game you choose, if you want all to be equal, you may feel the need to put in a few rules to balance it out. But I always enjoy playing Necromunda, and I seldom use House Rules.
I'd suggest you shelve "Underhive" and try and grab the original rules. Against Mordheim imo, it then becomes no contest.
Also, I had a look at some of the alternative gangs you've posted in the welcome thread, specifically the Orks gang. Would these gangs be accepted in the average Necromunda campaign? In other words, are they recognised as "official" gangs? I'm tossing up between Orks and Escher, and if Orks aren't official then I'll buy into the gang that is.
This is ultimately an issue that depends. A lot of groups will go with "official gangs" only. Technically anything published by SG is official, but anything not in the main books (or the remade Outlanders) can be problematic. I will say with regards to Necromunda that campaigns can suffer by having too few House Gangs, but never too many. Whilst I don't have issue with the Ork rules (they're actually rather underpowered, and not too great at that), it generally depends on who's doing what. A good Necro campaign tends to go well if it has a nice collection of House Gangs and a few oddballz.
When I arbitrate (GM, yes I sometimes GM Necro) I tend to offer various bonuses to encourage my players to field a nice variety, and impose limits and minimums to encourage players to balance the game out (Make a good thread that. Damn! Gotta do it now...).
I think the important step is to find out your group's tolerances. If this is an investment that you plan to use in multiple groups, then I'd go with Esher, although I've never really seen campaigns go through that actually turn people away. House Gangs will always get games, though. Sadly that includes Van Saar. Generally though if someone bitches about balance in Necro campaigns that take oddball Gangs, I tend to ask the organisers how many people are running Van Saar and Redemptionists. You often tend to find the organiser is running one of them.
It's a tough issue though. You need to be happy with your faction selection, especially as it's very likely you'll always use it. I however have multiple. I'd at the very least start
with a House Gang (Escher in your case) and if you want, branch out with a Outlaw gang or two. I plan to have modelling projects to make most of the outlander gangs, and I run Delaques (almost always), Goliaths and Skavvies as well.
In this day and age it's easier to see oddball gangs, as modelling is a big deal with a large proportion of the miniature collection gone on the wayside. One can spend a fortune on ebay buying out of print Necro models. So sometimes the modelling project is wiser.
I'm working on some Ork Gang rules for Necromunda. They wont have the prestige of being published, but they aught be a little better than the current ones.
If you want to know more, by all means ask further questions.
P.S. If you and your friends want to run Orks, don't forget about Gorkamorka! I have a pinned thread similar to my Welcome thread in the GoMo section with a few useful links if you're interested.