I figured it out---many courts on the east coast are more cushioned (not always on purpose-ours happen to be installed incorrectly & there is always a layer of water underneath the 1st few layers.) You may be familiar with the old San Jose ATP tournament the SAP Open; we supposedly use the same surface as there---Premier Court its called
http://www.premiercourt.com/what_is.htm & it is god awful. Says it's not a gritty court surface but judging by the way balls look after 5 sets of doubles, I'd say they're very gritty.