I really think Bob is on the right track. Not in the sense of offering a solution, but in terms of posing a question that will make you reevaluate the problem from a different angle. In general, I think this is a really helpful approach when confronting the problems of another person a) across a medium that tends to filter out a lot of information and b) that I do not (and perhaps most of us on RFF do not) know deeply.
I like the photos you posted. I think they show an ability to "see" rather than simply look. My observation about the current photo/tech marketplace is that there are a huge number of "flavors" to choose from and there is a tendency (at least I have this tendency) to think that there is a magic technological silver bullet out there. But this is not so. And this is why, about 10 years ago, I decided to insulate myself from gear-intensive magazines, even the better-written ones like Darkroom Techniques, and filter my "inputs" by seeking out only new images.
I spent some time today with the photo blog 500 Photographers, hosted by the NY Times.
http://500photographers.blogspot.com/ There is a lot of work I don't care for there, and some really awesome stuff. But all of the photographers hosted there have managed something that has eluded me: the development of a particular personal aesthetic. Maybe that is a place to start.
Good luck. Your sense of dissatisfaction with your work suggests a moment of real promise and possibility in terms of your development as a photographer. Congratulations!
Ben Marks
[Edit: Part of the reason I focused on the "zen" of this problem is that I do not know a lot about the various technical aspects of digital photography. In the wet-darkroom world I was a one-film, one developer kind of guy. You learn the tools, blah blah blah. I knew/know juuuust enough to get the look I want. I think that the sheer number of possibilities these days can be quite daunting -- color profiling my printer and monitor? Forgeddaboudit. The reason that I suggested the NYTimes link is that if you find a set of images with a style that speaks to you, you can ask around for how to achieve that "look" and build from there.
To do a 180 and focus on the technical for a moment: the sample pictures in your OP looked fine to me in terms of sharpness, but that may be due to the limitations of the "small screen" as a medium. May I ask, what is the output medium that you are using to judge the technical quality of your work? Every image will "break down" if you enlarge it enough (or stand too close). 0If you are dissatisfied with those, do try a nice sturdy tripod and consider a light meter so that you can take more control of the scenes in which you find yourself.
And finally, I found an old hard drive today that contained backups from 2003-2005. At the time I was using a Canon Rebel, and an Epson Rd-1. You know what? The "sharpness" sucked - was just terrible - viewed at 100% on my monitor. But taken for what they were, the images weren't that bad. Maybe you need to make a resolution to view the images no larger than 8x10 inches . . .
This is a nice RD-1 photo at a reasonable size (DR Summicron). Blow it up too much and its mush:
