I don't have much data but these are my impressions:
Portillo: base elevation 9,600, latitude <33 degrees, about like San Diego. Portillo is close to Aconcagua, average snowfall probably in the 350 range. Huge volatility, good years are 500+, bad years under 200.
Valle Nevado: base elevation similar to Portillo, about 50 air miles south, maybe a bit lower snowfall but overall should be similar. Both areas go up to ~12,000 feet.
I would hypothesize that the new snow is drier at the above areas than Sierra/Cascades despite similar distance to the Pacific because:
1) Ocean is colder
2) Altitude is much higher (except vs. Mammoth)
Sun will be intense at this latitude as I know from SoCal experience.
Las Lenas: base ~7,600 but it goes up almost 4,000 from there, latitude 35, similar to Taos. Snowfall is clearly less than Portillo/Valle Nevado but I don't know how much. With similar volatility bad years are so bad it barely opens.
Termas de Chillan: 5,200 - 8,800 latitude 37, similar to Mammoth "More snow falls here than at the Santiago resorts, but the powder is heavier," according to a Chilean website. I would expect overall snow conditions very similar to Cascades/North Tahoe.
Bariloche: 3,400 - 6,700 latitude 41, same as Colorado/Wyoming border. Snowfall at the top is just under 200 inches. Quote from
http://www.travelsur.net :"The reason Catedral is so popular is not the quality of the snow. In fact, it is possible to ski to the base only about 30% of the season as the hill faces east and the elevations are very low." Bariloche has lakes, scenery and the most developed resort town.