DADAMA  I have been looking for a replacement for Adobe Bridge. I was pleased to stumble upon gBrowser here in MacUpdate. Wow what a great piece of software. Nothing fancy but that's the just of it. It is lightening fast in comparison to Bridge and has some great features (e.g. file renaming, creating collections). It is missing one feature however and that is tagging/keywords; mind you Bridge doesn't support tagging either. Still, I am very impressed and paid for a license after an hour of use. I'll give it a solid 4 stars. Give me tagging and it gets 5.  
(Version 2.0b26)

EASER  I've come to very much like this program. I've been looking mostly for a simple but functional image viewer. I'd been using PhotoMechanic, but that was overkill for me, and updating to the newer version would be too pricy for my needs. Everyone has different needs and interests, but I've found gBrowser to be very fast and functional. It has a lot of customization options with key commands, icon and font sizes, etc. (The icons and fonts in PhotoMechanic's sidebar are teeny tiny, just as with Apple's Finder. It would seem that a lot of younger programmers simply do not comprehend what happens to your eyesight as you get older. You would think the ability to adjust these factors would be a given, but a lot of programs - including a lot of image viewing programs - do not offer this feature.)

In particular, though, I also like the responsiveness of the developer. There were a few features in gBrowser which, in retrospect, should have been obvious to me if I'd simply taken a few moments to look carefully at the preferences. Instead, I wrote to the developer to ask for help for how to work a few bells and whistles. Rather than chastising me, as some developers have, he took the time to walk me through the processes. (I once wrote to a developer about a sound editing program and asked how to do something. All he wrote to me was, "tinker with it, and you'll figure it out." I never did figure it out. That developer treated me more like an annoyance than a customer. So good customer service means a lot to me.)

I recommend that you at least give gBrowser a spin. I think the price is modest for the features and the support. And the developer seems very open to suggestions.   
(Version 2.0b23)

AN.ONYMOUS  Thank you Schwartz. It is all clear now.

I must definitely get used to the Windows-ish (now Mac-ish too) way to navigate through the HDs.  
(Version 2.0b22)

AN.ONYMOUS  Thank you for your reply, Schwartz.

1. I regret that adding the Coverflow option is not planned in the near future. Indeed, I have become so used to CoverFlow's smoothness and rapidity, and I find it so free and pleasant, that I can no longer bear discrete image shows.

2. To clarify the issue with folder moves : I could not directly open an image folder from gBrowser. I could only drag its icon from its location into the gBrowser window. Then, the folder is automatically displaced from its initial location into the User's "Image" Folder as Apple calls it.  
(Version 2.0b22)

AN.ONYMOUS  The main advantage of this app is its speed, especially when compared to GraphicConverter's slowliness in preparing slideshows of large folders.

HOWEVER, it has apparently the same defect as iPhoto and other tyrannic Apple apps: when a folder is selected it is automatically/definitively displaced to the Image Folder of the User Folder.  
(Version 2.0b22)

VINNYG  This application is fast, easy to use, the interface is great. I have used Graphic Converter for 15 years and now I finally have an alternate app to use when I don't need to edit. This is a well thought out program that loaded my folders of photos quickly ( average about 1000 per folder), borderless image views with right click capability to resize and super easy slide shows. This is the first time I have given a program 5 stars and this program certainly deserves it. Thanks to the developer for an excellent piece of work.  
(Version 2.0b15)

CANISBOS  This app is really turning into a very nice image browser/viewer.  
(Version 2.0b14)

DRDUL  I just downloaded gBrowser, and within five minutes of playing with it, purchased a licence. What a great app! gBrowser is what I've been looking for since I switched from Windows a couple of years ago (I had been an ACDSee user, and wanted something similar to browse images on the Mac). gBrowser offers just the right combination of features, simplicity and good looks, and the price is quite reasonable.  
(Version 2.0b4)

ANONYMOUS  This little app is becoming my image viewer of choice. It is not so overwhelming as iPhoto yet is certainly not so barren and the more basic apps. It's got some great features that set it apart from many of the others. The "Move To... " feature can assist in sorting thru a folder full of images in a hurry. There are other features not so readily apparent that would be beneficial to many. The develops seems to be quick and responsive - - and looks to be intent on making a good, workable browser. Give this one a look.   
(Version 1.6b18)

THOMAS NORDAM  Very nice image browser / viewer - better, faster (and cheaper) than iView media (pro). Thumbs up!  
(Version 1.5b22)