What is the "craftsman" warranty? Is that labor/installation? Because that's the one I'd focus on--gutters are cheap and will last. The metal won't break. I'd be much more worried about installation and repairs.

heimert...

Thanks for responding. The craftsman warranty covers the installation. Good point - more things to go wrong with installation than with the product itself.

I wonder which warranty sagging would be covered under? Is sagging due to inferior hangers (product) or how they were installed (craftsman).

I understand that that gutters should be anchored no more than 2 feet apart. My fascia board is 1x6 lumber - is this a sufficient substrate? Or should the gutters be anchored where the rafter tails meet the backside of the fascia?

Thanks again for your responses.

I have over-sized, heavy-gauge, galvanized gutters that are held in place with hidden hangers; there is no sagging. The hidden hangers are easier to remove if you ever have to do any maintenance as they are typically screwed in, rather than being pounded in.

You can get spikes that screw in now.
They are much better than the driven spikes, especially when they miss the rafter tails.

I lived in Fl also and found that I had to keep tapping the spikes back in all the time. When I replaced a gutter I asked for the hanger type but what I did not like is they cut notches in the drip edge that is on the edge of the roof and I thought that looked awful.The hangers are more secure but make sure they do not notch out the drip edge

These are also available at some of the big box stores.
Other colors also.

Here is a link that might be useful: screw in 'spikes'