rough-in for angle stops

Apologies if this is an extremely novice-like question, I am stuck trying to understand something.....

I am reading "Plumbing a House" by Peter Hemp in the For Pros by Pros series by Taunton. On page 150, talking about roughing-in toilet and lavatory, he has the water supply lines terminate at copper x FIP drop-eared 90s. The idea is that angle stops will thread into these 90s.

I have managed to figure out the terminology, which is never explained, but I am still trying to understand what the point is. Every other book I've read talks about putting a shutoff valve on the stubbed-out copper supply line. Perhaps they are assuming straight stops as opposed to angle stops? Does compression vs ball-valve stop have any relevance? I get the impression ball-valve is better than compression.

Perhaps there is further explanation in Hemp's sequel to this book, but it's out of print. If anyone can shed some light on this.....

The drop-ear fitting has ears that allow it to be screwed to blocking, thus keeping the end firmly in place. They often have a female theaded fitting in them, allowing you to use a screw-in shut off valve. Getting the fitting the right depth in the wall to make it look right takes a little skill. Using a copper 90-degree and a short piece of pipe sticking out of the wall means you can cut it off to the desired/needed length after the finished wall is installed. You should use a clamp to hold the pipe from moving (done with the drop-earred fitting if you use it instead). With that, you usually use a compression fitting to connect the valve to the pipe although you could sweat the valve or put on a threaded fitting, too. Ball valves turn on/off in 1/4-turn and rarely wear out as a shut-off. The more conventional valve has a rubber washer that can deteriorate eventually, and when you need to turn it off, doesn't. A ball valve should be either fully on or off, you get a little more flexibility with a conventional valve, but don't normally need it. My unprofessional take...

stops

The title or the book is misleading. It is not for "pros" and may not have been written by one. Few "pros" use drop ear elbows and threaded brass nipples to connect angle stops. Besides being expensive and more time consuming, and not having any advantages, there is no reason to do it that way. A "pro" uses a copper tube stubbed through the wall and it is cut to size and a compression angle stop is attached at the time the fixture is installed.

Thanks all for the clarifications. I guess the author likes the technique because then the angle stop is securely fastenened to the framing, but others think that this is overkill.

Edit: Oh wait the clamp anchors the stop with the "stub-out" technique. Maybe the point is that the shutoff valve can be changed without having to cut a piece off that stub-out, which would only give you so many opportunities to change the valve....

Edit again: But surely you could just sweat a female adaptor to the stub-out, so flexibility in changing valve isn't the issue..... And at least that way you wouldn't have one end of a threaded connection (nipple between elbow and valve) buried in the wall (I'm assuming sweated connections are more reliable than threaded connections)..... Perhaps there is some aesthetic about not having a copper pipe peeping out of the wall (for toilet supply say)....

stops

1. The copper stub out can be secured in many ways, compared to the only one available with the drop ear elbow.
2. When the angle stop has to be changed the nut and ferrule holding it can be reused or slid off so the new one can be used.
3. The copper is cut off so that the valve is close to the decorative flange so no copper is showing.

As I said, the title "for pros by pros" is misleading, or as Benny Hill would say, "That's not what it is, it's just what we call it".

When you are talking professional work, you have to realize that TIME is a BIG factor in the equation. Also, when you are talking 100 houses with a dozen or so stub outs, 3 or 4 bucks extra per stub out for cast elbows and nipples, now you are eating into an already meager profit margin.

It's not that a compromise in quality is being made. Any of the methods described will be equally long-lasting and no difference in professional appearance. But having to screw in those nipples, not to mention having to install a cap for testing, then remove the cap without unscrewing the nipple; all that compared to sweating in an elbow with sealed end stubout, then a quick cut on the stub to install the valve, the time saved cannot be ignored.

Thanks, this really helps a lot. Fully with everyone on the time vs questionable benefit point....

It seems like with the 2 approaches, there are two ways to connect with the angle stop:
(1) with the drop-ear, thread a nipple between the stop and the elbow,
(2) with the stub-out, compression fit the stop onto the stub.

Which connection is more reliable in the long term?

Apologies if I'm revealing the depth and breadth of my ignorance....

A shut off valve can need replacing after 20 years regardless of what pipe it's attached to.

Many older homes in the sixties used galvanized pipe nipple threaded into a drop ear 90, sweated to copper pipe.
After a number of years, the galvanized pipe closes down and needs replacement. If the pipe nipple is brass, that doesn't happen.
Brass does have some lead in it though.
If it were my home, I would prefer the compression stops.
If I need to replace them, I just use a sleeve puller.
There are fewer joints this way.

Ok thanks again for all the info.

Thanks also for the lead warning. In this case I'm looking at toilet supply, lavatory is in vanity, but in case anyone is reading this thread and.....

Aesthetically I think the nipple-stop-fixture line looks a little better, especially if the supply line is pitched high-ish in the wall to avoid 5-1/2" baseboard and leave room for 2-1/2" escutcheon. And the escutcheon doesn't have to be deep to hide the copper line. But when a plumber says "If it were my house,...." I will definitely pay attention.

I gather FIP adapter to stub out, nipple, angle stop is not a good setup . I think I've lost count of how many connections that has....

Now if only I could find ball valve stops in ORB, sigh.... Looks like Mountain only has compression stops.....

Thanks again for all the help!