Speeds have been really slow for me lately, regardless of port. I do have over 500 gbs transferred in under a month, however, DL speeds are even worse than I had Newshosting now. With newshosting, speeds would be throttled on the default port quickly and regularly, however, I never had that issue with Powerusenet. Up until lately that is. So I am almost certain my ISP isn't throttling specific ports. With PowerUsenet all the ports are pretty much the same speed regardless (all pretty much obviously throttled)
Overall service is decent, I guess, but way too slow for me. I also do not like not being able to upload at all. I think I will cancel this month, and try a different service. I had issues with Giganews tech support, before I had ever became a paying customer, so I won't touch them unless I absolutely have too.