Not very seedy, at least the one I harvested. I thought it tasted on the sweet side, my son said it was on the tart side, the wife said it was in the middle.
Alas, the cuke plants are dying - they don't seem capable of taking the heat, which is not that high - mid to upper 80s. But I've sowed some more so hopefully will have a bountiful harvest in late September or early October.
That one fruit was more than enough to fill a quart jar and I have at least three that are larger to pick.
Making note to self: get large plants outside no later than mid-May.
Mike