tested both for a few weeks. grabbed 100k requests with provider A's proxy api and 100k from provider B's proxy list. api avg cpm was like 2.8, bounce rate 15%. the list? same load but cpm fell to 1.9 and bounce shot up to 30%. why? api proxies are cleaner - less ip churn, less detection. list ones are more raw, often stale, more bans, more retries. data's clear tbh. if you want stability and speed go api. if you're just messing around or cheap? lists can work but expect slowdowns and bans. watch out for providers selling cheap lists with no freshness guarantee, i had one that got blocked in a day. api guys charge like 0.01 per request, list sellers do 1k ips for $20 but half are dead or flagged. imo if your budget's ok go api - saves time and headaches. but if you're starting out test both, keep an eye on bounce rate, and decide based on your sites and workload