I've been using ConTeXt for a few years and I'm curious about whether it is worth migrating to MKIV (I've just re-read the mk.pdf document).  Here are the features I often use:

  - Postscript fonts... I have typescripts setup for the fonts I bought (full versions of Utopia, Minion, Warnock, and a few compatible sans fonts).  I believe I can get these as open-type as well if needed.

  - Bibliography via \usemodule[bib]

  - Chemistry via \usemodule[chemic]

  - Inclusion of PDF figures using an XML Figure database, i.e. \usemodule[fig-base]

  - Equations (with the multiline and alignment macros) using Fourier/Utopia including the bold math modifications in the MyWay document.

  - Tables (tabulate, natural, linetable)

The questions I have:

  1) Do all of the above work in MKIV?

  2) How much of a pain is it to switch to MKIV?  Do I need to rework my fonts/typescripts?  Will all my current environments (setups, macros and one-line definitions) work?

  3) Beyond speed and better font support, does it offer anything else to me?

For the most part, I'm content with MKII and wonder if it is really worth the effort to move to MKIV.  Perhaps the sample is skewed, but after reading the mailing list I get the impression that the current experimental/beta MKIV has a number of bugs and is not particularly feature complete when compared to MKII.