There are other reforms which can accomplish much more than term limits, such as campaign finance reform, increased transparency, ethics regulations, and the emergence of 3rd party alternatives. However, the biggest difference would be made if people would simply vote. There is a democratic check on everything done by Congress.
This would do far more, no doubt about it.
Anyone has seen "Man of the Year", the movie about a comedian who becomes president. It's whimsical and far-fetched, but they have a great line in there.
"You can't raise 200 million in campaign funds and not owe somebody, something".
That cuts to the heart of the matter. These candidates go into office not beholding to the constituency, but beholding to their backers - ie major funders and lobby organizations. Cut the money off and bring the power back to the people.
Cynical as this is, the American people by and large are lemmings. Most people will vote Democrat or Republican - regardless of the body in the suit. And others will be swayed by who they see most, regardless of WHAT they see. And IMO, the later is more effective in the party races, the former comes to play in the presidential/congressional elections.
Cut the money back (drastically) get the message out effectively and not just en-mass. Make the elections real, not just popularity contests.
To that end, and for this one reason alone, I would find term limits desireable - once again the American electorate is by and large a bunch of lemmings. The incumbent is very often the sure win candidate, regardless of history. I've tried to recall the last time Iowa voted OUT as candidate for major office. Doesn't happen often. And more than I think they are doing a good job, poeple just get comfort levels and malaise.
Heck, if Eddie Murphy can become congressman just because he changes his name to Jeff Johnson and gets by on name recognition of a recently deceased incumbent, well you see how bad things are.....