Ran something over IRC today.
Party was a Medic, Tech-Priest, Heavy Gunner, and Storm Trooper.
First thing, the Comrades rules placement baffled everyone without fail. The entire book between rules for generation and rules for use just confused the group, and nobody wanted to keep track of them. They just gave the order for +3 damage each turn and ignored them. The rules for them taking a hit for you don't come up nearly often enough.
The Storm Trooper definitely needs the Ballistics Skill aptitude, and should maybe have that as his starting bonus instead of Toughness. The Medic did his job admirably, and scored a few kills with an acquired Grenade Launcher. Our Heavy Gunner had a blast; his Heavy Flamer (named 'Suzie') devastated the enemy, with one poor heretic suffering three Righteous Fury hits from one attack (a total of 45 damage.) The tech-priest found himself a little bored, with a lack of a distinct niche beyond "guy who opens doors." He enjoyed his Servitor though, using it to grapple an enemy general that he then executed with a mechadendrite.
They all seemed to enjoy my homebrew Valkyrie (being a door gunner is fun when you're packing a Heavy Bolter) and were happy to have flak armour to keep them safe. One player remarked that he enjoyed the simplicity of it much more than Dark Heresy, and they enjoyed the more limited focus of the game.
A lack of weapons with Pen seemed to be an issue, with many rounds of combat being lucky hits that did no damage.
Overall, a real blast!