Crawlers cast a more critical eye to URLs with a lot of parameters, particularly if a lot are numeric. They don't want to get caught in an infinite loop of indexing the same content where the parameters may not change the actual content.
Crawlers don't care if you use ampersands and equal-signs to separate words in your URL, or if you use forward-slashes. So-called search engine friendly URL's are no more nor less friendly to search engines, than other URLs. They may be friendlier to humans, though.