Currently, you can serve three two-year terms in the Assembly, and two four-year terms in the Senate; a total of fourteen years. The initiative will lower the total to twelve years, but allow those to be served in a single house (or as eight years in the Assembly plus four in the Senate, or whatever).
I dislike term limits in general. It takes a long time serving in a legislature to really learn all the things you need to know about an area of policy -- and to make connections and build alliances across regions, across interest groups, and across party lines -- to pass a major policy. Under current circumstances, even in the non-term-limited federal legislature, lobbyists get more respect than House members, and frequently dictate policy directly. Term limits only aggravate these problems -- they ensure that the person with the most experience and connections, in relation to a given policy, will be a lobbyist, not a legislator.
Term limits also create a "musical chairs" effect, where politicians who want to have a career in public service have to be constantly planning their next jump -- which drives the need for more money to fund campaigns. (An incumbent campaign is cheaper than a campaign for a new office.)
Term limits ensure that legislators identify more strongly with their party and its base than with their legislative colleagues or any particular policy project. They thus help drive the partisan gridlock that maintains our structural budget deficit and prevents movement on ideas like ending gerrymandering.
John Vasconcellos represented Silicon Valley in the state leg for 38 years, during which time he drove policies as diverse as: moving towards a "harm reduction" model in dealing with drugs; creating a trade and engagement plan between California and Japan (which, considering the many collaborations between Silicon Valley and Japanese high-tech companies, is an important story); and authoring the AB 1725, which basically created California Community College system as it functions today (which, despite cuts to CA's ed system over the years, remains quite good -- see, for instance, the De Anza Environmental Studies program).
I'd be OK with a limit like "30 years in the legislature, 40 years total in state gov't service (including state leg and executive offices)". But I think twelve is kinda short. How many of Vasconcellos' achievments would never have gotten through if somebody with his collected experience and influence had not been behind them? What happens if there isn't anyone with that experience and influence? Do we end up having to rely on people who become overnight sensations through charisma and media adulation? Sometimes a sensational figure really does have fabulous ideas and can make major reforms quickly; but sometimes the media falls for somebody who's basically a narcissistic sociopath. Not that I have any current U.S. Presidents in mind, or anything. :-P
I'm kind of torn about this initiative; I dislike the reduction, but on the other hand, as Ira Ruskin pointed out to me the other day when I asked whether he was supporting it, he's been unable to pass the feebate bill, AB 493*, so far. If he has to bail out of the Assembly and make a run for the Senate (potentially having to run a primary campaign against another local Dem, somebody he'd presumably rather be collaborating with), that will set back his efforts. If he can spend a full twelve years in the Assembly, there's a much greater chance that he'll eventually get AB 493, or something similar, through the process.
* BTW, if you're in CA but not in Ruskin's district, please write to your Assemblyperson and State Senator and tell them to get behind AB 493!
So, I'm leaning towards voting for the initiative. But I hope that eventually people will wake up to the fact that term-limits do not actually work as originally advertised. They make needed reforms harder to achieve, and ensure greater influence and access for lobbyists. If this can be a step towards keeping the "in both houses" concept, but raising the number of years, that would be nice...