I wanted to let them know I appreciated things like tightening the screws on a loose hinge or cleaning out a hair clog from the bathtub. 

Our landlord, on the other hand, never hears from us, we pay rent on time, and we keep her place clean and maintained nicely -- it actually looks way better now than it did when we moved in, because we've repaired crumbly wall sections, spackled holes/dents, touched up scratched doors and floorboards, de-stained the linoleum, replaced cracked lightswitch plates, power-washed the patio, washed the blinds (the landlord didn't, there was cat hair embedded in them from a previous tenant, which by the way the landlord wasn't aware of anyone having a cat, LOL), etc.  

Any market difference is going to be splitting hairs when it comes to the bottom line of your portfolio.

He has red hair but I can't think of his name at the moment. 

I do like redfin a tad better, not a fan of the zestimate, but i use these sites to just comb through and if i happen to find one i get more detailednimfo from agents

My mom a hair salon with 3 apartments over them my father a landscaping business and also has 3 units over his garage where he keeps his equipment.

you can have a decent website for $2000 or less these days depending on the complexity of the website you have in mind, so not necessary splitting hairs over this. 

I would still double check your findings by combing through craigslist.

Go through your lease with a fine tooth comb and if they are late on payments, make sure to stick to that eviction process.

@Jason James did you cut your hair man??