I have no experience with DM/Shield (I have played /Shield however). I won't comment on this combination.
As far as DM/Fire I rerolled my scrapper (played to level 50) as a brute and I like it much better. I admit the majority of my experience with the scrapper was well before the juicy changes to /Fiery, so take that into account.
I would still recommend the brute over the scrapper for several reason:
The brute seems much more survivable, (yet still squishy at times).
The brute soul mastery app was a superior choice IMO. It offers tools that improve survivability while having the potential of improving ST and AoE damage. Gloom is that good!
Brute fury affects Burn. I don't believe this can crit for scrappers.
The /Fiery damage aura has a taunt component for brutes. For scrappers it does not. With the current changes to Burn some scrappers are still reporting "run" behavior from mobs. I think taunt aura is the big difference.
It appears Fiery Embrace can benefit from brute fury as well. It does not appear this gets any benefit from the scrapper inherent. (I cannot verify the second part)
Don't get me wrong by my presentation of the Pros of going brute, there are advantages of going scrapper. From my personal experience the combo plays better for me on a brute.
Best of luck making your selection.
So, I haven't played a Dark Melee toon since my DM/SR brute, who I got bored with due to pretty much being without AoE power. I'm looking for a new DM character who can put out some decent AoE as well, so my natural choices were Fire and Shields. Dark synergizes very well with both sets for obvious reasons, and I know DM/Shield is pretty much the FOTY, but I already have a Fire/Shield scrapper I absolutely love, and a SS/Shield brute on his way. So I'd like to try Fire, but is the squishiness gonna be too much of a pain? Dark adds a lot to toughness, and Dark/Fire just seems really cool, and the AoE damage will obviously be better, but is it worth losing the survivability?
Thanks in advance
P.S. As DM/Shield, obviously I'd be a scrapper, but with DM/Fire, would scrap or brute be better?
P.P.S. I suppose DM/Elec is also an option, since it has a damage aura, and the infinite endurance would make it much easier to go after Fire Ball or something.
Sound off for me!