To me one of the biggest changes that has to be made is to put benefits on a actuarial sound basis. As rule early retirement reductions are not nearly severe enough and things like buying pension credits are too cheap. So I applaud Ohio for doing this politically painful steps now, when the crisis is meal acute rather than waiting another decade or two and ending up like Detroit.
clifp has nailed the crux of the Ohio situation, IMHO. Old system did not have realistic early retirement reductions, cost of buying credits, and control of spiking. They've adjusted those and added an anti spiking formula that prevents crazy payouts relative to amount contributed.
Under the old system, $250/month income was considered "full time". There were folks who had small hour government positions (think a meeting or two a month in a small county or something) yet got credit. They could do 27 years of that, contribute next to nothing, then get a real job at a real salary and have 3 years to get FAS up, and collect on a formula that counted all the years, but only the FAS. The $250 was set in the 70s with no adjustment for inflation. The anti-spiking formula will look at lifetime contributions and limit the payout. IMHO it is still generous to someone who has legitimately moved up the pay amount, just not crazy.
The full retirement age changes to benefits were not as significant. Work an extra year or two, that sort of thing. The big hit to the already earned time is for those who were doing as the OP planned and retiring early. Changes aren't being made to benefits being paid already, but there was notice provided that you had to retire by such and such a date to get in under the old system. But not everyone is eligible to retire by that point.
While I'm affected by this, I also applaud them for making the changes. I think it's the right thing to do for the long term health of the system, which is in my best interest since I don't want to see something like Rhode Island. To my knowledge, everyone's been paying in, not skipping contributions like some in the news. And for my personal situation, I have the proverbial multi-legged retirement stool... assets in taxable, IRAs, SS, a modest pension.. no single one of those income streams will be enough to retire on, but in combination they will work, and that makes me diversified in the event that something happens to one... In my case this means most likely delaying drawing the pension until I hit the full age, which may/may not be reduced by inflation as well...
Ironically, they also offer an additional annuity, whereby someone who is a member can pay more and get paid an annuity. It's not additional credit, the idea is an SPIA but without the sales charges. I understand these payout rates are subject to change, but in the case of their estimator the difference between taking a payout at 60 vs 66 is nowhere near as big as the early retirement reduction. I routinely see folks complain about taxpayers footing the bill, but in this situation the people who hit the full retirement and collect are doing it in part on the backs of those who go early or don't hit the full amount.