[detruncate]

Yes, the rake has an impact, but that's only one factor.

I think there are a few other things going on:

1) Your (true) winrate is probably quite a bit less than it was at .5/1, meaning that downswings are going to be more common.

2) People frequently overestimate their winrate at .5/1... especially since they usually move up when they're "crushing" the game for what seems like a lot of hands, but isn't nearly enough to narrow things down to a reasonable range. A few good sessions can have a huge effect on your winrate even after playing several tens of thousands of hands. This isn't to say that people should spend more time at .5/1... just that honest self evaluation is much more useful than what PT tells you you've been earning/100 hands.

3) People usually move up after running well for a while, and therefore find themselves "regressing to the mean" at an unfamiliar limit.

4) The pot size might not seem that different, but you may end up contributing a higher % on average due to a fewer players seeing the flop and beyond.

5) People are nervous and/or affected more than usual by bad beats/runs given the fact that they're playing an unfamiliar game (often thought to be harder). The general difficulties re. maintaining confidence are amplified. As is the perceived impact of mistakes.

6) The changing $ figures is an added stress.

7) Your losses will be proportionally greater (relative to the size of your bankroll) due to the fact that saving up for a move leaves you significantly over-rolled at your previous limit.

8) The character of the average game at your new limit is probably different than at your old one, which therefore necessitates moving out of your comfort zone more often than you're used to.

9) The games are often harder for one reason or another (fewer poor players, more better ones, greater aggression, smaller pot sizes, etc.)

10) The effect that bonus $ + rakeback has had on the bankroll building process is often not fully acknowledged.

I'm sure there are others. It's not that important, really. Do your best to accurately evaluate your strengths and weaknesses, and play at a limit you can afford. End of story.