I played my very first game using the AdMech forces I've been painting over the weekend. It was a ton of fun, but the army didn't do particularly well.
My army was as such...
Space Marines Combined Arms Detachment (Primary)
Scout Sergeant Telion
10 man Scout Squad w/Sniper Rifles and a Missile Launcher
5 man Scout Squad w/Bolt Pistol and CCW riding in a Land Speeder Storm
1 Drop Pod (for the Arc Rangers below)
Officio Assassinorum Detachment
Skitarii Battle Maniple Detachment
10 man Rangers Squad w/2 Arquebuses
5 man Rangers Squad w/2 Arc Rifles and an Arc Pistol
6 man Vanguard Squad w/2 Plasma Calivers
5 man Sicarian Infiltrators Squad
5 man Sicarian Ruststalkers Squad
1 Sydonian Dragoon
1 Onager Dunecrawler
1 Plasma Obliterator
The Skitarii elements were actually pretty solid. The Dragoon and both Sicarian units were rock stars. The Sicarians held up 6 Wraiths and 10 of the jump Necrons for basically the entire game. They would have chewed through softer units. The Wraiths having a 3++ is a killer.
The real issue with my list was that the Space Marines, the Vindicare and the Plasma Obliterator were almost entirely useless. I don't think any of them made their points back. As much as I want sniper rifles to be useful, they just aren't. The Vindicare has less than a 50% chance of doing a wound, assuming you stay away from Hellfire rounds. That's not very good for a 150 point model. The Plasma Oblit clocks in at 230 and MAYBE made it's points back.
I need to rethink the Space Marine elements. I think I might be far better off using Tau Empire as allies until I can invest in a larger AdMech army. I love the idea of the Conclave formation, but that would entail buying an Imperial Knight as well as about 6 boxes of Cult Mechanicus. I might end up going that route, but only if I can find a way to save up and afford it. I have so many unfinished projects, that I've cut my hobby budget back pretty dramatically.