Growing up in an older neighborhood and then moving into one myself I had an idea the older plumbing might be an issue and from day one both bathroom showers wouldn't drain well. After about 4 months of dealing with a slow drain I started looking for a plumber that works the Arcadia neighborhood and found these guys from a Nextdoor.com recommendation. For $50 a drain they do fast work. So fast it almost seems unbelievable that they did anything but the last 3 weeks the drains have worked as though they were brand new.
The tech said he almost exclusively works our neighborhood and even was able to come out within 2 hours of my call (though he did say it's slow in the summer time, probably why). He even took the time to tell me what I can do to keep the drains running great and where I can go buy this enzyme stuff.
I hope I don't need to call them again anytime soon but I know for an easy $50 they will be back out quickly to fix it again.