The way I see things is that once you reach a certain amount of SP, you start to progress almost on autopilote just by commenting and upvoting. It was very hard to reach minnow level but then it started to get interesting because there were actually curation rewards coming in. The more SP, the more curation rewards and the faster the progress.
Congrats on 30'000 SP, this brings you into the top 700 Steem Power holders!
source: https://steemitboard.com/ranking/?p=113&s=posts&hl=jongolson
Absolutely. I really noticed a big change when I hit around 1k Steem Power...Back then 1k Steem Power was like 10 cent upvote or something LOL But the more I plugged into the community, the more I seemed to grow.