1:01 p.m. on August 26, 2011 (EDT)
After many different pairs of boots I am a non gore-tex fan in footwear.
I believe a membrane has its place but footwear is not one of them. I am a big fan of my Scarpas. If taken care of leather will keep your feet just as dry as a boot with a membrane...
Then again I also use gaiters. (these are for wet weather only I have another pair for snow.) Moisture can penetrate the inside of your footwear through the exposed portion of your socks(above collar) and gradually work its way downward into your boot regardless of how "waterproof" they are.

I think people have just become lazy in a sense and do not want to maintain their gear unless absolutely necessary. With a FGL boot w/o a membrane you do have to maintain them. I am an Obenhaufs die hard when it comes to my boots. I wouldn't use it on nubuck though...

I do not like gore-tex for a few reasons that I have stated many times.
When a membrane is combined with a FGL boot it is complete overkill. Not too mention they do not breathe and they turn my feet into sweatboxes which equals to "hamburger foot" when travelling longer distances for days on end.
When Gore-tex is combined with a boot that has synthetic(ie Cordura) inserts it works fairly well but still leaves a bit to be desired imho. I personally do not like synthetic boots because of the rocky terrain I encounter and they just don't last for me.
I am not sure if the OP has ever gotten a FGL boot that has a membrane wet but they take forever to dry. Alot longer than a boot w/o a membrane.
Then there is the whole durability thing with gore-tex. In time they will leak if used regularly in harsh conditions. It seems to me that the gore-tex breaks down pretty fast.
Being they do not breathe well this can big an issue in cold temps. Perspiration is moisture, moisture in cold temps is a bad thing. Granted this may not be an issue in the desert but things like blisters, trenchfoot, etc are.
I believe alot of companies implement a membrane into their footwear to cut corners when it comes to the attention to detail in regards to production. I have compared the stitching on my non membrane boots to my boots with membranes. There is definitely a noticeable difference.
If they blow a stitch on a boot with a membrane no worries, the gore-tex will cover their tails.
On the Renegades.... The nubuck will need to be treated so it doesn't suck water up like a sponge. I would suggest using NikWax Nubuck and Suede Proof. Even if ya go for the ones with Gore-tex it will not hinder what breathability the boots have. Here is a link for it.
http://www.nikwax.com/en-gb/products/productdetail.php?productid=77&activity=
I have learned that after prolonged times of being saturated regardless of whether or not you have a membrane in a boot they will eventually leak. lets face it, if water wants in bad enough it will get in.
Not too mention the extra added weight a pair of water-logged boots will add.
If ya want the most out of your investment take care of it.
Welcome to Trailspace SassZiggi, happy hiking.
***On a side note the Renegade is not one of Lowas heavier boots, its actually one of their lighter boots. Ya may want to upgrade if durability is a concern especially if you are hauling a heavier pack. I think they are pretty much in the same group as the Zephyrs as far as intended use goes. Lowa classifies these as a hiking boot, not a trekking or backpacking boot. Here is a link for that as well.***
http://www.lowaboots.com/catalog/SelectType.cfm?Category=3&CFID=48824929&CFTOKEN=18960705
I just checked the Zephyr is a hiking boot as well. This type of boot is typically designed for light trail use/weekend trips with a light pack/daypack.
I would definitely consider looking into something heavier. While more expensive initially it will be easier on the ol wallet in the long run because they will last longer and you will not be shelling out more money on another pair.