Does the first reflection point actually matter??

Yes I have. Quads and Accustats. Both ultimately set up about 5 ft from the back wall and I used diffusion on the back wall mostly between the speakers. No side wall considerations were necessary due to the limited horizontal dispersion patterns of both speakers.

By your question you seem to assume that 1st reflection points are correctly treated by using panels etc. I suspect that there are other and, perhaps, better ways and this is often just a band aid approach which facilitates placing the speakers too close to a wall. 

It seems that many folks want the appearance of a super wide soundstage which is best effected by utilizing the first reflection point. When they do this, IMHO, the combination of direct and 1st point reflections contribute substantially to a reduction in clarity. And a reduction in depth of image as well. If you don't hear this, with or without panels, as you seem not to do, then perhaps you are listening for the wrong thing, i.e. 'brightness'. 

Personally I find drilling down correct speaker placement and appropriate toe in are a far better solution to the problem of side wall reflections than just putting a foam panel on the wall, etc. 

FWIW.

 

BTW Eric, you seem to only be concerned with 1st reflections off the outside side wall. Don’t forget the effect of 1st reflections off the back wall, floor and ceiling. All important I think. Also consider the propriety of using the LE/DE methodology in setting up your room. When using box speakers I’ve always found a LE/DE set up (or something close to) best.

IMHO, this subject is almost as complex as rocket science due to the fact that the the results of set up and room treatments, most all of the sound folks hear is subjectively judged. Not a bad thing in itself but due to divergent expectations hardly a scientific approach (if one could even be heard). FWIW, I find it interesting reading recommendations for room corrections. Especially corner traps to improve low bass. Folks should look at an anechoic room and see what is really involved in setting up control of bass waves. Makes one wonder about ’bass traps’ typically recommended.

But to answer your original question, Yes 1st reflection points do matter and how you deal with them (not ’treat’ them) is very important if your goal is to obtain clarity and well developed 3 dimensional imaging. IMHO anyway.

Not exactly on point, but close 

For those of you who want to have the greatest clarity from your speakers and have decided to put 1st point reflection killers on the outer sides of your speakers already, try putting an identical pair on the inside of your speakers. This will effectively give you as sharp/clear signal as you will ever get. If you want that kind of signal - If you have no wife - If your not anal about the physical appearance.  

Many years ago I had a product called Echo Muffs which was, in essence a 5' high U shaped heavy latex pad wrapped around and close the sides and rear of the speaker and projecting forward about 6 inches in front of the speaker. Boy, did it work! Sort of like a poor man's LE/DE room.
Then I got married! :-)