To answer the question directly, I can enumerate some of the differences between GenomeBrowse and IGV. IGV is the established player for sure and there are many features there that have grown on the product over the years that are not yet in GenomeBrowse (or that don't make sense as GenomeBrowse does things like zoom or stacking differently).
GenomeBrowse is written in C++/Qt and heavily uses asynchronous I/O and multiple threads to do your rendering. That buys you very fluid interactions with the data as you pan and zoom. We also put a lot of effort into making sure sure we keep the pile-up of reads very stable as you pan so you don't loose track of specific reads you might be interested in that hang off the edge of your screen. IGV "re-stacks" as you pan.
GenomeBrowse auto-generates coverage data (as well as BAI indexes if those are not available) for your BAM files. IGV has the concept of coverage data at zoom levels where it doesn't makes sense to draw reads, but you have to compute it on the command line outside the tool. GenomeBrowse also displays forward/reverse alignments coverage in the "Coverage" track, while showing max-depth and max-mismatch depth in the pile-up track at far out zoom levels. This provides a very fluid experience in tracking your genomic features as you zoom around. For RNA-Seq data you will see gapped-alignment depths over introns at these far out zoom levels.
GenomeBrowse does not have a fixed height for it's pile-up stack after which you don't see reads (you can set this to be quite high in IGV, but it has a limit). Instead, we have a very dynamic Y-axis (you can note as you pan left and right the smoothly adjust the y-axis scale). You can also zoom with the scroll wheel by default and we "smart zoom" at a certain level so you can dive into a single read level's detail and zoom back out. You can also unlock the auto-Y axis scaling and have a fixed Y scale where you can zoom and pan the Y axis as you like.
GenomeBrowse has a lot of annotation tracks curated and you can view them immediately by streaming them (loading only what's need for the current view) from the network servers. You can also download them if are going to use them alot and want them to load faster.
GenomeBrowse displays indels in the coverage view of BAM files. IGV does not. We show little orange "][" bars between the two bases where the insertion resided. You can click on these to see the allele counts at that site.
GenomeBrowse goes through great extents to label data on screen when there is space (for some plot types, you can choose what field is used as the label). The labeling is dynamic so as you zoom in and there is more whitespace around features, they get labels drawn. This is all for the purpose of making screenshots have high information density for publication or sharing.
GenomeBrowse groups genes with the same name and gives them a big "group label" as well as labels transcripts and amino acids as you zoom in. Especially when you have overlapping transcripts from different genes, this can help clarify which transcripts belong to which genes.
GenomeBrowse has hover-based labels for things like amin-acids in genes, depth counts in coverage, mismatched nucleotides in reads or genotypes of individuals in VCF as well as the ability to click on any feature and get all the fields for that feature in a persistent Data Console window. IGV shows much of the same data on hover, but then you can't select that data and copy it since in it's a tooltip like hover window.
When GenomeBrowse filters reads (see the gear button on pile-ups), you can see a "hashed" coverage of the original read depth versus the filtered read depth. IGV has a lot of filter options, but filtered reads are not shown in their coverage view (I believe you can set to still see them as greyed out reads in the pile-up window though).
I would change the title to request an opinion without the qualifier of "any good" that seems a little bit judgmental from the get go.
I have downloaded the tool but I found the interface confusing and did not pursue it further - but I admit that I did not spend too much time with it.
Then some time later (2-3 months) when I wanted to look at it again it denied running saying that my license expired and that I would be required to download a new version. It was then when I noticed that it also installed a hidden program something called "licensing server" that I believe was always running in the background even when the browser was not active. I found both of these practices unacceptable, first that they can revoke my access at any time as well as installing hidden programs that are not visible or known to me.
Overall this turned me off from using this tool or recommending it to others.
As it turned out later and explained by a representative of the company this has been a misunderstanding on my part. The tool was hard coded to expire and the licensing server must have been installed by some other software.
I apologize for the incorrect statements made with respect of this software.
I have downloaded and checked the MacOS version superficially due to Istvan's concerns. The mac package does not contain any file such as "licen[sc]e". Also, after starting the GenomeBrowser I didn't see any suspicious processes. That should not be interpreted as if mean to say the software is safe or clean, or anything. Certainly, use of a free and "open-source" model would be recommended. I would also recommend to consider the FOS approach to you, Gabe. That will easily deflect any mistrust that could possibly arise, so the "FUD" you Gabe are complaining about, is partly the result of the closed source approach, so you better get used to it.
The registration process was fairly quick, it asked for the main contact data including phone and email, in principle you have to enter them all, but it seemingly doesn't make an attempt to validate them in any way. I would have no problem to register a software with my office address and phone if it was really good and could be used in a project.
Showstopper: not being able to import my own genome and annotation. In my project, are working with sea lice, which have no public genome yet, and hence are not in the list. Otherwise I might have recommended GenomeBrowse, as one of many alternatives in a list of "free" tools, as it is now, it is unfortunately no alternative to IGV at all. So here come my 2ct for making a successful genome browser:
Make it open-source
Allow users to import their own reference and tracks