Yes, yes and HOLY BEANS YES!
You may feel a little 'let down' to begin with a it's only 3 maps, 4 classes (out of 10 total) and a handful of weapons right now but it's such good fun I don't really care. Haven't seen any instability or crashes from it yet, possibly the rarest of lag spikes during mega firefights but that's to be expected. Full content rollout will be coming along as it's finished, and I actually believe Tripwire on that.
Tripwire did extremely well for the owners of Killing Floor, loads of new maps, new content, new skins and weapons, and only towards the end of the 'life' of KF did they start introducing extra paid-for weapon packs, and although not essential to the game they did improve it (flare pistols. I want my flare pistols of murder!)
For £20, get it... you'll enjoy it with randommers, but get a 4, 5 or 6 of OcUK lot together or some regular friends who play it and it gets a whole load better. (especially when people play to the strengths of their class)