Preface: OK I am going to preface everything I say with some information about myself. I was in multiple top 100 US WoW guilds with many top 100 achievements including Firefighter 25, One Light 25, and many more (getting old now but still valid). I have been within top 100 in many other games... and sometimes within top 10. I have 50 million gil in FF14... probably within top 3 on my server... and that game would have many of you people screaming like girls. I have played lots and lots of games... and usually do very well at them. I have already paid real money for CE in Spiral Knights... and I enjoy Spiral Knights very much.
That said... even though I have already paid real money to play Spiral Knights.......... being unable to play an unlimited amount of time is absolutely terrible for this game and will drive almost everyone away but a very small minority. It is no secret you can only play about a hour a day before you run out of mist energy. This is very very bad... even though I see some people try to justify it for whatever reason. Fact is when people can only play a hour a day.... they will only play a hour a day and then go play something else (which is really bad... for this game). I already see way less people around... and I really doubt it's because the game fault... because this game is really fun.
So here's the main problem as I see it. The main problem is the fact you pay 10 energy going down each level. This has absolutely got to go. Paying energy to upgrade your weapons/armor is absolutely fine... and this would still make you need energy and buy it. But limiting game time by making you pay every time you go down a floor is a absolute disaster. Paying 10 Energy each and every floor absolutely has to go.
Let's look at League of Legends... probably one of the most popular games out there. And let's be real... it's not popular because it's good. In fact it's not... but you can play a unlimited amount for free and use real money to buy extras. And even still.... Riot will make waaaaaay more money off League of Legends than the dev's make off Spiral Knights.
I am a paying player.... I pay to play good games. But paying real money for a limited amount of gametime (which is 100% true in this game) is a absolute disaster and will probably turn me off eventually from playing this game.... and probably the vast majority of people who try this game out.
Edit: I just want to add I don't mind paying 10-15 bucks a month to play a game... especially a game like this. But when I get a limited amount of playtime (which is 100% true for Spiral Knights) for my 10-15 bucks (only 35 hours per $10 spent based on 100CE/hour dungeon crawling)..... this is REALLY REALLY BAD and will make me think twice about continuing it play. To the vast majority it will make them stop playing.
I agree with most if not all of this.
If they remove the 10ce/floor cost most players would quit bitching about CE because then they would only need it to craft.
However, if you stop to think about it, I believe the developers have picked this specific model to FORCE people to HAVE TO purchase CE, and that is my major complaint.