This may seem sacrilegious, but I've found that the White Labs tubes are pitcahable in 5g of wort, and I've pitched smack packs right into 5g of wort too and they both attenuated just fine.
I honestly prefer dry yeast and only use liquid if I really need to tweak a beer with a liquid strain. In this brewers opinion, unless you're doing more than 5 gallons at a time or making some higher gravity beers, I can't think of a reason to make a starter if you stick with liquid... To answer your question, in my experience, both White labs and Wyeast have yield quality results, get the one best suits your brewing needs. If you find two similar strains, go with the cheaper one

I like Whitelabs though, dont have to worry about "smacking the pack", just let it warm up, shake and then pour it into your wort. Viola! You made beer.
Not to hi-jack, but a local 7bbl microbrewery uses Safale dry yeast exclusively and the brewer pitches at most 2 packets directly into the wort... no re hydrating/proofing, certainly no starters. Lets not forget that yeast is a living thing and given favorable conditions, it will reproduce as needed.