Hi all. How different are these 2 lakes? If we spend some time on L. Guarda, what would be unique to see over on Lake Como?

Worlds of difference !
The north end of Garda has the same mountain scenery but not the rest. And, Como is much more refined--- beautiful villas and gardens etc. I refer to Lake Como as Newport RI on the shores of Lake Tahoe--does that make sense?

Bob pretty much hit the nail on the head.

Also, if you are using the boats, rather than a rental car: on Garda the north-south boats run about every two hours. On Como at mid-lake (where most tourists stay) there are boats coming and going almost contantly.

Thanks. Where are your favorite places on l como?

The mid-lake triangle--especially Varenna and Bellagio.

if you are a fan of thermal water like we are, try sirmione. you can take a soak there, or, just go out in the lake, where there are areas of warm water coming up from the ground. sirmione is a more rugged area, where you will want to drive around the lake and try some amazing local fish here and there. if you go, we just loved il griffone... in the historic center. book a room on the water (you will hear the water lapping and it's just beautiful.) however, this is a minimum-service place and small rooms. the old town is great in the evenings after the many tourists head out.

como is very upscale and lovely... and as someone mentioned, the mid-lake towns are just great. at como, you will likely see the sites by ferry, which is relaxing.

with a car, i vote for garda. with no car, i would go to como.
hope it helps,
-kawh

On Lake Como, Varenna is a small town with a fishing village feel to it. Relatively quiet at night. Bellagio has a resort feel with lots of options for hotels, shopping, restaurants and bars. I imagine that most visit the other town regardless of where their hotel is.

Mostly Lake Como is about relaxing. The mountains and lake create breathtaking views. I recommend a visit to one of the gardens or gardens and villas that are open to the public. The public boats stop at more than a dozen different lake-front towns. These towns can be fun to explore. We like the various towns when have their market days but that might not appeal to you.

The mid-lake area is very english language adept.