stp questions

With 802.1w how normal is it for an environment with 8 switches ~300 ports with to exhibit 1-3 seconds of packet losss/latency/jitter everytime any port transitions to STP forwarding and causes topology change notices to ripple through the entire stp domain? The ports causing this are connected to end-user devices, not the uplink/trunk ports. Is it reasonable to expect the vendor (not cisco) to support a port link-type that - does not cause topology changes to ripple through the domain - does not cause 1-2 seconds packet drops when transitioning to forwarding - transitions to forwarding quickly AND - blocks accidental loops ? IOW everything that I get from portfast and rpvst. Thanks. Joe