@ kuli the integrated chat system is should be here soon, though the Zwift App. Expecting a map update this week or next (probably London expansion judging by the silly amount of London days this month), so maybe voice will be in with that.
@ eyedrops I actually find intervals on Zwift fantastic, not sure what kuli meant about some guy passing him on the off interval making it 'pointless'. Just don't understand what that sentence means. Maybe he can explain. The training plans generally are okay, they have all the main plans to suit the majority of riders, but once you want to get more specific while being structured then you're on your own. They just don't have enough plans. Though they do now have loads of individual workouts since the GCN update.
Re: carbon bikes - we use carbon bikes, three of them, on the Tacx Neo and there's no problem. That said, you really need to make sure the dropouts are sitting flush on the rear axle, and that it's on tight. Any play whatsoever will grind the dropouts away. Personally, if I had a metal frame, I'd use that instead anyway, well at least for sprint intervals. We use the cheapest £400 chinese carbon frame for most training, but we do also use the posh bikes as well.
When it comes to getting 95% of the performance of a 1k machine - then that's the Tacx Flux. Not really any competitor to it. It's best bang for buck right now. It had some launch issues but should be resolved now. I have the Neo and ERG mode is screwed on it since the last update, so paying more doesn't guarantee you a flawless experience over all updates.
About your power meter - the last update a month ago means that you can now use your own power meter in ERG mode. You could always use it before, but not in ERG, so even if you buy a dumb trainer, you can still get the benefit of all training options now.
Also Apple TV is in beta, so you can also consider that as an option when looking as cards and costs etc.
People improve a lot on Zwift, and fast, it's definitely good fun. I know there's a ton of updates coming this year and it'll keep most people happy, but for me, unless I see more training plans, I might have to look elsewhere and maybe just replicate it on Zwift. I know some guys are paying for 2 subscriptions - trainerroad for the plans, then overlaying that on Zwift. Can't see me paying that though