Tips from one who just put in marble & soapstone
My counters have been in for not quite a week now, and here are my gut impressions. (Soapstone is on the more heavily used L of my counter areas, while marble is on the lesser used other side of my kitchen; I don't have an island. This was a kitchen refresh rather than a gut or new construction.)
I've got an older house with 1920's to 1930's era, natural birch cabinetry (honey toned) some original and some custom replicas. The floors are maple that also have a honey tone. Obviously the counter looks are completely different and, if I look at only the one surface at a time, the kitchen has a totally different feel and look. The soapstone area seems quite similar to what many people today are installing in Craftsmen type kitchens, while the marble has a more undefinable by era look. The darker soapstone definitely soaks up the light whereas the lighter marble doesn't. I'm glad the soapstone is on the side of my kitchen where the windows are because I think it might be overwhelmingly dark in an area without really good natural lighting.
In retrospect, I overanalyzed this choice because I got so caught up in all of the discussions here of density and hardness and scratching. I eliminated some choices I probably would have liked better just because they weren't as hard and might be more vulnerable to scratching. Even the quite hard (original PA) I installed does get small scratches from everyday use. Now that I understand this, and see that it does not bother me, if I had it to do over again, I'd pick more on looks rather than being so concerned about all of this scratching/hardness issue. I'd been hoping to leave it unwaxed and unoiled because I like the lighter appearance better, but I'm already seeing that grease spots appear very easily when unoiled. I'm still trying to work out a good method to deal with these spots and may end up going the waxing/oiling route despite the fact I'd prefer the lighter appearance.
Marble--It's lovely, and in some ways I wish I'd had the guts to use it all over. But, it has not really had any wear or any use so I haven't been dealing with etching or everyday maintenance issues, and I hear these are much more apparent in really well-lit areas (like the areas where my soapstone are). Mine has been sealed three times, so I am hoping it does well. Interestingly enough, my fabricator commented to me that he can tell when he first comes out to measure whether people will have problems with marble or not. He thinks people who keep the kitchen fairly well maintained are those for whom it will work. He said we should be fine, and we are not neat freaks by any stretch of the imagination.
I like the mix of both materials. Appearance wise I think I would have liked all marble. I don't know if I would have been happy with all soapstone (just because it is so dark) unless I'd chosen a different type than I selected.
I got lots of help here, so I hope this helps others who are going through the throes of decision making. I decided to post this now because I think most people, unless it was really a horrid decision on their part, adjust to whatever they have installed and forget their early impressions.