Which is better for driving?

The Chamelo Music Shield, because the tint slider lets you cut glare as light changes. The Shokz has a fixed lens, so glare control depends on the lens you pick.

Which lasts longer on a charge?

The Shokz OpenMeet, rated up to 15 hours. Chamelo does not publish a battery figure for the Music Shield.

Are the Shokz better for phone calls?

Yes. Shokz lists four amplifiers, 11x18 mm speakers, and 98.6% noise reduction. Chamelo lists audio but no call specs.

Is the Chamelo worth stepping up to?

If you want one pair for sun and sound with adjustable tint, yes. If you mostly take calls and need long battery, the Shokz fits better.

Which is lighter to wear all day?

The Chamelo at 49 g versus 78 g for the Shokz. The gap is noticeable over long wear.

Do the Shokz work with a laptop?

Yes. Shokz lists Windows 8+ and macOS 10.15+ support. Chamelo does not list computer compatibility.

Chamelo Music Shield vs Shokz OpenMeet Audio Sunglasses

Buy the Chamelo Music Shield if you want one pair that handles both sun and sound with a tint you can change on the fly. Buy the Shokz OpenMeet if battery life and call clarity matter more than lens flexibility. The Chamelo is the lighter pair at 49 g versus 78 g, and its adjustable smoke lens is the feature the Shokz lacks. The Shokz counters with up to 15 hours of battery, Bluetooth 5.4, and a four-amplifier setup tuned for voice.

Choose the Chamelo Music Shield if you want adjustable tint and a lighter frame in a single pair of audio sunglasses.
Choose the Shokz OpenMeet if long battery life and clear calls are your priority.

Prices

Chamelo Music Shield: $113.90 at eBay (last seen Nov 9)
Shokz OpenMeet Audio Sunglasses: $119.95 at Amazon (checked today)
Difference: the Chamelo Music Shield is $6.05 cheaper than the Shokz OpenMeet Audio Sunglasses at the latest prices (Nov 9 and Nov 11)