For the individual account it will depend on how many votes you previously were receiving prior to 30 minutes and even knowing that we can't tell for sure if it will be net positive or negative until we know the actual amounts returned to the reward pool under HF20. Then we can calculate what the rshares received on your posts would have actually been worth when your posts paid out. It is not enough to just say you would have lost X amount from votes that came in before 30 minutes; that is only part of the equation.
Even though you are technically a "small" account it wouldn't surprise me if you personally will lose out at least a small portion under HF20, as you are definitely punching above your SP weight in terms of your average post reward.
But you also will not be one of the big losers - accounts that previously were using the 0 minute self vote to maximum effect were sometimes getting up to 800% ROI on the self vote, and the best they will hope to get under HF20 is 100% (as @tcpolymath points out in the comments here, 100% ROI at least is easily attainable by self-voting comments). That is still a huge difference of course - the accounts that combined large voting stake with use of the 0 minute self vote were previously commanding a hugely disproportionate share of the total reward pool.
The share of the reward pool dominated by 50K+ SP accounts will decrease - that is a net positive for everyone else.