I've been using a manual Craftsman 5-blade reel mower for years. It's
OK for most of my mowing, but it has some shortcomings:
Doesn't cut grass stalks.

Bad with long grass.

Bad with grass that spreads out in a circle rather than grows up.

I've searched a lot online, and I've read that 7-blade mowers are
better (for all types of grass?), that reel mowers with no-contact
blades are better (easier to push, and rarely need sharpening). I see
a few 7-blade, and a few no-contact, but none that are both.

I also see an interesting looking cordless 5-blade reel from Sunlawn
that's really light and apparently can be used as a manual too.

Should I expect these mowers to cut my long/difficult grass, stalks,
etc?

In your experience, will a high-end manual or cordless mower seriously
outperform a basic one?

There are a few cordless rotaries as well. Most are very heavy, and two
that seem to get good reviews (black & decker & neuton) are pretty
expensive. Would they do better with difficult grass?

I know a gas mower would, and I could get one for occasional use.

Thanks!