Grindelwald

Jerry, Grindelwald is a good place (and so is Lauterbrunnen, Wengen, Mürren).
Heading south from Interlaken, the valley splits in two, Grindelwald to the left Lauterbrunnen, Wengen, Mürren to the right.
This "map" may help to explain the local geography, red lines are railways, black are cable cars: http://www.regiopass-berneroberland.ch/themes/bls/images/map/map_2016.jpg

Grindlewald is not in the RS guidebook because it's a resort and it's very touristy. He'd rather recommend one of the alternatives in the area: Wengen, Lauterbrunnen, Murren, and especially Gimmelwald. Grindlewald is perfectly fine if you prefer a resort to the more out-of-the-way towns, but you will need a different guidebook to cover it.

Hmm, Wengen, Lauterbrunnen and Mürren aren't resorts and aren't touristy? You could have fooled me, with all those tourists, hotels, restaurants, mountain sports shops, etc.

I actually prefer Grindelwald in the winter, because it provides the easiest access to the best skiing in the area. You get a pretty good view of the impressive north face of the Eiger from almost everywhere in the town. The downside is that if you prefer your resort traffic-free, Grindenwald has a street running through the middle. It doesn't have that hemmed-feeling of Mürren or Wengen, which could be a plus or minus, depending on your perspective. Getting to the Jungfraujoch is easier from Grindelwald and Wengen and getting to Piz Gloria on the Schilthorn is easier from Lauterbrunnen and Mürren, if that helps make up your mind.

Tom - the Globus Tour Buses should have been your first clue that Grindelwald is the most touristy and heavily trafficked. You won't find tour buses in Wenge, Murren or Gimmelwald.

Just saying... it seems kind of odd to call one place out as a "touristy resort" when all the towns are also filled with tourists and the same related infrastructure (except perhaps Gimmelwald, which has the tourists but not the infrastructure). But the towns aren't the reason to visit, it's the mountains.

I'm just saying RS probably considers Grindlewald to be too touristy for his taste for him to recommend it. The others are certainly less so.

If you plan on several days, then you should stay in one of those towns. Otherwise you would pay the extra fare to come into the area every day. If you have never been, then I would suggest Murren for a couple of days and then Grindelwald. There are a lot of great hikes on the Grindelwald side. Don't miss Kleine Scheidegg! And the views from First are wonderful. Enjoy!

Per your question, Grindelwald or Wengen (but I prefer Grindelwald), are perfect for exploring the area. From somewhere like Murren, which a lot of people love, you explore--Murren, and maybe Gimmelwald.

I get the 'stay in the mountains' and for that I love the SAC-CAS huts, many at the end of a beautiful gondola ride others at the end of a long day of hiking, all high in God's country.

For exploring an area I typically stay in a valley town.

If it makes you feel any better many TINY Swiss towns are considered 'resorts' due to their vicinity to skiing. Grindelwald falls on the smaller end of this (although not the smallest) while Zermatt would represent the larger end.

We're staying 4 nights in the BO in July and picked Wengen over Grindelwald because we wanted to be up on the mountain rather than in the valley. We also considered Murren and Lauterbrunnen but felt Wengen would meet our needs (including logistical) the best.

We spent five nights in Grindelwald, didn't find it "touristy", no buses ever seen. It is a mountain resort, very well situated to visit other towns as well as the lakes below.