We had a plumber out to fix a toilet that was experiencing slower flushes and causing frequent blockage. The toilet had been snaked and auged and seemed to be flushing fine when he was on-site. We also both went out to the yard and watched the flow to the street through the main clean out. The plumber thought the flow rate was fairly strong and was frankly confused as to why we would be having problems. He suggested that the next step was to do a video of the line to the street, but again, due to the strong flow he didn't feel this was the issue. Our home was built in 1958 and the toilets may be original, they say "Standard". His suggestion was to replace the toilets. Due to their age and appearance this is something we're willing to do regardless (considering the Toto Drake II), but in speaking with a few people they don't think it's very likely to be a problem with the toilet itself.
Thanks for any help you can provide,