I just came back from a larger dealer who has both brands. The Giant actually has _five_ models of the Revive. The dealer had three in his store. One of the Giant Revive's has 21 gears.
There are plus and minuses of both brands. The Giant is lighter and one model has 21 gears, but I really like the back support of the Gazelle better. The back support of the Gazelle is an open mesh material which helps keep your back from sweating. For most of you, this is a moot point as the Gazelle is probably only sold here in Holland and maybe Belgium as well.
The Giant model I rode, the Revive DD, had a neat feature - a built in speedometer. It was built into the steering bar.
Re lights - I believe _all_ bikes in Holland are required to have lights. If I am wrong, I'm sure someone will correct me. The five models from Giant ranged in price from (in Euros) € 649 for the basic Revive to € 1,999 for the electric version, the EB (four speeds). According to the Giant literature I have in front of me, the basic model seems not to have any lights, the other four models do.
The Gazelle would be my first choice if it came with more speeds. As usual, I can never be entirely happy with any decision. In the middle of October (here in Utrecht), there's a big bike fair, Bike Motion, and Giant will be represented.
I am planning to wait a few months to see what if any newer models are offered from Gazelle and Batavus (another Dutch brand). I'll keep you posted. I imagine that Batavus (and probably other brands as well) will offer similar models.