Wyeast is the yeast my LHBS stocks so it's what I use. I would love it if they carried White also but understand why they don't.
I have only used liquid yeast once since I've only been brewing for about a year. It was WLP810 San Francisco Lager. I suppose that we are all swayed if unconsciously by marketing. The first book I read was The Joy of Homebrewing by John Palmer. He clearly has a relationship with White Labs. I think that and his excitement about steam beer steered me out of my comfort zone and led me to that yeast. Incidentally, I just bottled a Märzen that I brewed on top of my steam beer yeast cake and have high hopes that it will be a great beer.
Charlie Papazian wrote the Joy of Homebrewing, and his "Cry Havoc" yeast is carried by White Labs.
I have only used liquid yeast once since I've only been brewing for about a year. It was WLP810 San Francisco Lager. I suppose that we are all swayed if unconsciously by marketing. The first book I read was The Joy of Homebrewing by John Palmer. He clearly has a relationship with White Labs. I think that and his excitement about steam beer steered me out of my comfort zone and led me to that yeast. Incidentally, I just bottled a Märzen that I brewed on top of my steam beer yeast cake and have high hopes that it will be a great beer.
White Labs has had some issues with sacc contamination of their Lacto and Brett strains.
Also, when I submit questions via email, Wyeast responds within the hour. White Labs takes a few days.
They both have quality products though. You can't go wrong, really. It's more about what strain you like.
I'm a newbie, but it seems like it comes down to personal preference or what the recipe you're following calls for.
I found this article interesting in comparing two similar yeasts from the two companies:
http://brulosophy.com/2015/08/31/yeast-comparison-white-labs-wlp029-vs-wyeast-wy2565-xbmt-results/
Some tasters preferred the Wyeast, others preferred the White Labs. The takeaway for me is they do produce different beers.
Keep in mind that while WY2565 and WLP029 are both "Kolsch" strains, they are not purported to be from the same brewery such as WY3522/WLP550, or WLP565/WY3724, etc. I don't know if they knew this at the time of the experiment or not, but to me the whole effort kinda seems moot
Ask any homebrewer that has made their fare share of Kolsch beers and theyll tell you the two are definitely different
I didn't even realize the two companies produced identical yeasts, shows how much I know
Do most White Labs yeasts have a corresponding Wyeast yeast?
Actually it's about 50/50 -- often there are corresponding yeasts, but very often not. And even when they are supposedly from the same source, inevitably even if you were to run an experiment and split a batch with the same wort and ferment with each one separately, they will always actually taste noticeably different. The reason is that they are farmed by the different companies with slightly different techniques, and also the yeast multiply very quickly so there is perceptible evolution going on at this accelerated rate, so the same yeast actually can only stay similar for a very very short time. You can even try this at home, brewing the same recipe twice but using the yeast cake from the first batch to ferment the second and subsequent batches. The character from any individual strain repitched will often change slightly from one batch to the very next. But, if the yeasts were sourced by two (or more) commercial manufacturers 5 or 10 or 20 or 30 years ago, or maybe more, then just imagine how different they could become after so many reproductive cycles.
Case in point: WLP820 and Wyeast 2206 are supposedly from the same source and thus equivalent. Ha! Maybe they were the same at one time, but it must have been a VERY long time ago. In my experience, this "equivalency" could not be further from the truth! I have used a lot of different lager yeasts over the yeasts, and of all of these, WLP820 is just about my least favorite of all, while 2206 is my all-time favorite. They are extremely different. WLP820 has a long lag time and underattenuates consistently, while Wyeast 2206 does not have these problems and gives the most elegant "German" flavor of any yeast I have used. And if you experiment with other "equivalents", you'll likely find the same truth with any others as well.
Cheers.