Don't know if this is the right subforum, but I did in the past. I've always like bikes but there have been large parts of my life that I just needed a cheap old bike so it wouldn't be a nice steal and it usually got stolen anyway and I had to get a new one, so I wasn't very precise about the features. Two roundish wheels was the main concern. I always like the oma design most, but these days I park my bike inside and I demand a good return on speed for effort. So I ride a tall men's roadster these days.
Step throughs are considerably more wobbly and the energy that goes into the flexing of the frame doesn't go into forward motion. For me that means riding at 20 km/h gets a sweaty job on a step through and I don't want to sweat cycling, for cycling slowly it doesnt matter that much. But I'm quite tall and about 90 kg, I guess the wobble is much less a problem for lighter and shorter people. I assume the modern wide tube aluminium step throughs are more rigid but not as rigid as their top tube counterparts, and I'd probably get me a double top tube model. So the question probably is whether it is the step throuhg you liked so much or the upright position and the 'lazy' geometry, that comes with top tube bikes too.