is it a good idea to Ally with daemons? fielding a T7 possibly T10 can really make a difference

I find the great unclean one very useful against space marines, IG, Necrons, orks, etc... The only problem i have with him
- Us Dark Eldar Laugh at how fat and unhealthy the great unclean one is, they think he moves in slow motion.
- Were a little desperate sometimes at allying with someone
- the GUO can be ignored altogether by the master race Eldar and Us. Fast armies will make this thing useless
- T10 can be ignored by Us and Tyranids
- hes very slow and not very purposeful when he can only move 6 inches and not run.
But there isnt only cons to the GUO
- Really Really hard to inflict a single wound on him provided if your a faction that shoots lasguns or bolters or gauss.
- A big distraction to your opponent when he knows that thing can contest objectives
- he normally has a 2+ cover save beacuse of shrouded and stealth (provided if you hug cover)
- hes only 190 points to begin with
- he has 6 wounds possible 7 from greater rewards
- he hits very hard as he's a MC
- Papa Nurgle's Psychic powers are to be feared( they are pretty strong)

In conclusion i believe he's a good choice because he can contest and distract the opponent long enough to give me an advantage

I don't think it would add much beyond what a Talos provides when you consider the increased cost plus the troop choice tax, and the fact demons are desperate allies. It still might be fun though.

The problem with a GUO is that he is too slow to really do much damage. If you are looking for a distraction unit, then he might be fine. But there are better allies that can do it all, and you still get something out of them.

If you do daemon allies, I think a flying slaanesh DP w/ whip is probably your best shot. Get him as your HQ and min troop, and your golden