I would usually steer way clear of Originative due to a very bad reputation here over a few disputes, im not sure how they are like now, but many people feel scammed from them.
On the other hand, Geekkeys is run by Feng, a very reputable sellar on ebay and a great GB hoster here, so that should be fine.
To answer your question, some ABS keys have a REALLY grainy texture, even moreso than the natural sandyness from PBT, but unless you're super sensitive and picky, theres nothing to worry about. (Although ABS can start shining relatively sooner, but since mods dont really get used that often, then meh)