toiletusa
Why is it that in most home or apartment environments you find toilet seats that look pretty much like this:
And yet in offices and public places you will most often find toilet seats that look like this (although many also without the lid):
What is the deal with the open front?
I ask this because I always wonder when I DIY replace old toilet seats if I should select the second style.
The hole in question is a siphon jet. It concentrates flow from the tank, jump-starting the siphoning effect.
If you look close (I’m not suggesting you do), there’s a siphon jet hole (see letter G on diagram) in the bottom of the toilet bowl. It’s hard to see unless you put your head in the toilet (For the record, I didn’t do this). When you flush, water shoots out of this hole to fill the drain pipe. This creates a siphon.
When I investigated, it was plugged. Eureka! I cleaned it out and once again heard that perfect flush. -tomlaforce.com
See (acid), How to clean under the narrow toilet rim to restore full flush power
When you flush the toilet in the diagram, the chamber directly above the X fills with water. This chamber is connected to the same passage where the air is, above G. It's also where all the holes are and once they fill with water, the air is forced out through G.
A noticed change may be a clog somewhere but perhaps as the guest toilet, you never realized how poorly it preformed out of the box. IME this is typical of low-flow toilets but also of every toilet that hasn't been flushed in a while.
You may be interested in adjusting or installing a chain float which will hopefully allow enough water to flow after the bubble pops, to create a siphon.
"If left alone with water input off, the tank water level will lower (perhaps 1/4" in 1 or 2 hours), and puddle will be present near front of toilet. This suggests to me a bad job of installing wax seal"
There is an important clue buried within your question. There is no water from the toilet present at the wax-ring seal except when flushing.
Your problem/leak had nothing to do with your wax ring!
Best Answer
It’s a “Public” and “Private” toilet issue.
Health Departments and plumbing codes require the “open front” seat in public restrooms.
It’s a sanitation issue. Here’s why: http://mentalfloss.com/article/64677/why-are-public-toilet-seats-u-shaped