I've "successfully" converted one of the infoboxes, throwables, to the new format (on a test template so as to not affect existing pages Template:Infobox test1) and have a working example on my sandbox page. It's missing a lot of the styling, since I cannot access the .css pages for the Wikia. As well, a lot of the text seems to be difficult to edit. For aesthetics sake, it may pay off to hold on any kind of conversions you may have planned.
Some of the issues I ran into were:
Invariable text sizes
Poor positioning of text on the templates
Semi-confusing syntax (although, I suppose I'm just biased since I like the old syntax)
Some pros, however include:
None to minor changes needed on the current pages using the templates. It seems viable to make the converted template use the same inputs, so the infoboxes currently on pages do not need to be changed.
Human readable syntax
Doesn't look terrible in it's default CSS state
Feel free to edit my sandbox as you please as well as the template I've linked.
I wanted to, @Hassat, but stylizing the text in the template is currently impossible. I can't center anything. And there is 100% nothing wrong with Rhyzak's. I actually think we should stick with his/hers until Wikia gives us more control with their new system. It looks better, works better, and overall is just a better option for our current needs.
However, if you need a breakdown of what test1 is, I'll go and codenote up the syntax. Should make it easier to read.
I'm still really new to the Wikia, so if this needs to be handled differently, let me know. Don't want to mess anything up.