I use 10% dextrose in my Pale. In order to keep up I brew a high gravity batch where I add 3 BBls of H2O prior to fermentation to net 17BBls. I use WLP001 and dont notice any cidery flavors. Fruitiness with 001 seems more related to gravity and temp than any dextrose I add. I find that it suits my goal better than adding light malt extract because I like a dry crisp finish in the pale where the hops take center stage and the dextrose helps me achieve that. I wouldnt reccomend it in a beer where you want maltiness or more palate fullness. I also mash higher than normal and use carafoam to make up for the thinning effect of dextrose. It also helps keep the color light and is easier to add than malt extract. I have never used straight maltose. You definately have to experiment and account for the thinning effect. Its also handy for boosting high gravity beers when you have an undersized mash tun like I do. Dextrose definately has its place but can be abused. I tried it on several of my beers to try and increase capacity but the pale is the only one I actually like it in other than strong specials. You can also invert the dextrose by adding citric acid for belgians but that is adressed in another thread. I would be interested in hearing how adding dextrose effects malty low attenuating strains if anyone has any experience.
"You are what you is." FZ