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

- blocks accidental loops


IOW everything that I get from portfast and rpvst.