My wife bought “the rav Moshe Haggadah” and in it rav Moshe says romaine is better than horseradish because it’s just like the shibud it was sweet in the beginning and then it became bitter
Romaine is the best form of maror to use. Radicchio isn’t mentioned as suitable, and no poskim ever used it. Some, including Rav Aharon Kotler, would use iceberg lettuce. I’ve seen iceberg used in communal sedarim because it’s cheaper than romaine, and poses less of a tolaim concern, although there are still bugs in iceberg.
since the nasal passages, to which horseradish fumes rise, are connected to the eyes lacrimal canals, a good chrain does tend to produce tears. Maybe that’s an additional maaleh of horseradish.
Romaine was always considered “bitter” because of the hardship in cleaning it from bugs. With Bodek romaine that no longer is the case. However, I learned in a shiur that romaine is the major of choice, because the Gemarah says what is chazeres? Chassa (lettuce). Within the name of chassa, spelled Ches Samech Hei, is found the expression of Chas Hashem. Hashem is chas (Meracheim) on us, especially in our most bitter times.