Is low-e or regular (clear) glass better for a solarium?

The south side of our house is a solarium. Two walls 6-ft apart with sliding glass doors in both. An overhang blocks direct sun in the summer, allows it to shine in in winter. We need to replace the outer sets of doors.

The old doors are clear glass. The builder said that, since it’s a solarium, you want the sun to shine through. The contractor we’re talking to for the new doors says we should use low-e glass. He says we’d lose about as much heat at night through the clear glass than we’d gain during the day. I also guess that the solarium would be cooler in the summer.

Which would be best?