Installing Wall Vent on Stucco Exterior Wall

[greatscott]

I am installing a new wall exhaust vent for our range hood and my outside wall is stucco.  I have two options:  surface mount the vent against the stucco (just cutting out a 6" hole in the stucco) and using adhesive sealant to adhere the vent to the stucco.  The other option is cut the 6 inch hole in the stucco but also chip away the surrounding stucco so the vent is flush-mounted against the plywood of the house and then pay someone to re-stucco it (whatever is involved with that).  My original thought was to go with option 2 as I'm paying someone to come out anyways to stucco up the old vent that I'm removing (the new vent is in a different location) but the majority of help sites I find online are doing option 1.  Is there a benefit to doing option 2 over option 1?  While option 1 is easier, is option 2 the better option for making sure I don't have potential leaks down the road?  If I go option 2, I would be doing all the work with getting the holes cut and the vent installed and the stucco guy would take over from there and I have a pretty good idea of what I need to do.  I ordered the wood-boring hole saw and diamond hole saw (for cutting the stucco) and waiting for those to be delivered so I have a few days before I begin the work.  Just wanted to gather thoughts on this before I proceed.  

[Willyou]

Without knowing more about it, I would guess that the only advantage of option 2 is aesthetics. This "flush" mount (or close to it) might look better on the outside of the house. However, It seems to me that this might also create a "pocket" where water can more easily infiltrate. A surface mount (option 1) can be sealed around the edges directly to the stucco and with the stucco intact, any leakage would still have a ways to go before it gets to the wood. Either way, I think that once the hole is cut, I would seal the exposed area at the wood/stucco layer.

[Cabinet Monkey]

Option one is how 99% of jobs are done anyway.  

It also makes for easier maintenance / replacement down the road if/when that becomes necessary.