Question about getting thinner tires for a hybrid

[KnottedYet]

I have Vittoria Randonneurs on two of my bikes (both are cyclocross) one with 32mm and one with 28mm.

I'm an airhead when I ride, and like a magpie I will swoop in upon anything shiney or glittery... so far both sets of tires have survived riding over a variety of sharp shiney things. Both have ridden on a fair bit of gravel, the 32mm more than the 28mm.

Handling on gravel feels the same to me 32mm vs 28mm, though I can tell on one of my other bikes that the 23mm tires on that bike make the handling a bit more squirrelly in gravel. (though the 23 mm are not so squirrelly that a couple hours on gravel isn't just fine).

I don't think you can really go wrong with either width of tire. If it were me riding your Marin and choosing between 25mm and 28mm, I'd go for the 28mm. Mostly because I know aluminum drives me nuts and I'd want the juicier tires.

ETA: I'm curious to know how you are going to put the Junebug into a 25.4 mm stem, and what you are doing with the levers and shifters. If you are switching out levers and shifters and bars and stem and getting travel agents for the brakes... would it be better to hang onto the money and just change out the tires for now? Tires alone will make a big difference, and you could save a good bit of money for your new bike that way. At one point I wanted to convert my Kona Dew to drop bars, but the cost of all the bits added up was nearly what I paid for the bike in the first place. And was about 1/3 the price of the cx bike I bought next.