"They are not glassy at all. Ok, maybe they devitrified, unlikely, but possible."

Your assumptions are that Mars atmsophere and gravity are like that Earth, but this is not true. The impacted material would not have to go to a true glass state.

" Well, then how are they all so perfectly round?"

Exactly. Mars lacks the volcanism for round gas pockets to form, and there is no other spherical mechanism except for impact condensate.

" Why is the size distribution so limited?"

Mars atmosphere and gravity are constant.

"If they formed in space, as some unknown type of chondrule, then at least a good fraction would have become unrounded on re-entry, and show signs of ablation. If they formed as tektites, molten material thrown out by impacts which rapidly cools to glass, then how is it that none of them have the teardrop, disk, or dumbell shape typical of tektites?"

You're assuming that the accretions reached sub-orbital velocity. Mars' gravity is different than that of the Earth's. The hot impact dust (not molten material) would simply remain "air-borne" longer.

"Being composed principally of hematite, where is the source rock that could have produced them?"

Try any iron impactor.

"While there are several other theories which are still plausable, your tektite theory lacks credibility."

I hope that I've answered your objections.

ep