I'm sure that you've made your decision already, but in case anyone else out there is still contemplating, we have the Ticor S405D and our window comes down to the counter with no bumpout. We don't have any issues with splashing- occasionally it happens if we're washing something very large, but it is certainly uncommon. Also with our granite countertops, we have no gaps that are in danger of water, should splashing occur. I suspect that having gaps is more of a function of poor workmanship than anything else. I researched the counterheight windows extensively before we put them in, and have seen many threads on them afterwards, and the post above is the only one I've ever seen that states that water or gaps are an issue.

Oh dear, you must be upset. I wish I could help. Our sink is held up with a 2 by 4 shelf because we have a very deep sink and my DH wanted it to be supported. So strong a small dog or baby could take a bath. I am sure Stonegirl or Kevin will chime in. They are the experts. I did find a few quotes from some granite installers and how they support sinks. Maybe this can help you figure out what is going on with your own situation. I also included a few links I found searching. I wish you luck. ~boxerpups Quotes from the link http://www.stoneworld.com/Articles/Feature_Article/BNP_GUID_9-5-2006_A_10000000000000334891 ".....After the sink is laid out, we take a 5-inch Makita grinder and butterfly the stone to about a depth of ½ inch. Then we use lead anchors submerged in flowing polyester. Once the glue is dry, we flat grind the glue off flush with a wet cup wheel. This allows our installers to use a #10 machine screw with a wing nut to tighten or draw the sink clips up to the sink....." ".....One of the challenges facing fabricators now are oversized sinks (as Dustin noted). These sinks are larger in both width and length. In some situations, the overall size of the sink (lip to lip) is larger than the inside cavity of the cabinet. There is not very much room to put anchors in  if at all. In these situations, we inform the customer of the problem. If the customer is still adamant on using the sink, then we show the customer our route to solving the problem. We use the router on the side cabinets to allow the sink lip to sit on and flush to the top of the cabinet. This is fail-proof, but it would be difficult to remove the sink in the future if needed...." ".....We almost exclusively fabricate 3-cm material. For most stone, I like to outline the sink flange and grind tapered slots into the granite. We mount the sink using sink clips, flat head machine bolts, wing nuts and silicone. For softer stone or cast iron sinks, I build a wood frame (or occasionally sink setters) to cradle the sink in place. In my opinion, fastening the sink mechanically is fool proof...." http://www.diynetwork.com/how-to/how-to-install-an-undermount-kitchen-sink/index.html http://store.graniteearth.com/greaunsiinto.html http://www.ehow.com/how_4963264_install-undermount-granite-sinks.html?ref=fuel&utm_source=yahoo&utm_medium=ssp&utm_campaign=yssp_art

CloudSwift - your poolside view is amazing and I absolutely love the double sided sill - that's awesome! Lizzard - that's exactly what we had in mind - thank you so much for your post and picture - that's the exact setup we had in mind - with the sill, the granite and then the tile every where else. Did they have a name for what that section of granite is called? Was there a particular edge that you used for this? That is the other thing that I need to make a decision about - the edge in the magazine pic is a double bullnose (I think?), but we wanted something simpler, like what you have Lizzard - so having a name for it would help. Thanks everyone for your replies!

@Darlene. You may wish to start a new thread. There are several professionals here willing to help. Yes you can fill a small gap with setting mortar depending on the mortars limitations. Some form of backing or reinforcement will be needed. As I stated above always go directly to manufacturers for installation instructions. Yes showers have a high degree of difficulty with a lot of details that must be followed. If you choose to proceed please purchase a TCNA Handbook. A $35 investment well worth it. You must use caution when seeking advise nowadays. I have found YouTube will have more bad info then good. Again go to the manufacturers videos! Unfortunately Handy Huber with his 1 project experience has resorted to name calling while providing you with bad advice. "then you have to run the cement board vertically from bottom to top." FACT Cement board is installed horizontally with staggered seams. ANSI 108.11 page 57 A-4.8.5.1.4 Cement board recommendations such as "new piece so that it's snug" "nice and tight." FACT The manufacturer instructions state leave a gap. https://www.usg.com/content/dam/USG_Marketing_Communications/united_states/product_promotional_materials/finished_assets/usg-durock-cement-board-with-edgeguard-installation-guide-en-CB237EG.pdf "And most importantly make sure when you get to tiling that you use trim tile ALL around the window frame! It's a crucial extra layer of protection against the constantly wet conditions and protecting the seams." FACT Tile has nothing to do with waterproofing. If you can't run the shower without tile it is not constructed properly. Many feel as I that showers are not a DIY project. Can it be done? Certainly. It's all in the details. Good luck with your project.