I had been fairly happy with Catalook until 1) I realised it's not truly multi-currency and 2) a minorbug I identified resulted in the feature being removed.
I stuck with a version that's a few months old to maintain the feature that's recently been removed.
The feature was the pricing could be entered as tax inclusive rather than exclusive and it worked fine except the calculation of the tax compenent wasn't actually applied when a purchaser was tax exempt (though it was showing the tax calculation).
Instead of fixing the bug which I clearly pointed out (screenshots, access to server etc) this feature was removed as the develop said they couldn't reduce tax from a price inclusive of tax though they were able to add tax on. This meant prices are all considered to be entered tax exclusive - though as a manufacturer/wholesaler and online retailer - our focus on presenting price was purely the rrp (ie tax inclusive). So I chose to remain with a version that's a few months old.
Now Catalook needs a separate version to be installed to be compatible with DNN 5. On a test server this is difficult in itself since the Catalook version for DNN5 is lower than it is for DNN4 so it prevents installation.
What I'm stuck with now is being forced to upgrade Catalook to run of DNN5 and then losing the previous feature of entering tax inclusive pricing or remain with DNN4.
This is really just the venting of a frustration that's been 6+ months since the bug was discovered and then having the feature simply removed. Now developers (not only Catalook) don't have modules upgrading nearly as smoothly as I can see with the DNN Core modules. 3rd party modules are the biggest DNN 4 to 5 headache.