Could iteratee depend on mtl instead of transformers?

[Johan Tibell]

On Tue, Nov 17, 2009 at 9:19 AM, Nicolas Pouillard
<nicolas.pouillard at gmail.com> wrote:
> Excerpts from Edward Kmett's message of Tue Nov 17 05:03:01 +0100 2009:
>> On Mon, Nov 16, 2009 at 8:42 PM, Erik de Castro Lopo
>> <mle+hs at mega-nerd.com<mle%2Bhs at mega-nerd.com>
>> > Popularity is not the issue. The issue is that we are currently
>> > in a transition from using mtl to using transformers. See:
>> >
>> >   http://www.haskell.org/pipermail/libraries/2009-March/011415.html
>> >   http://www.haskell.org/pipermail/haskell-cafe/2009-October/067744.html
>> >
>> >
>> Are we?
>
> Let's make a poll then!

I went back and reread the two linked threads and I'm no wiser as to
why we should prefer transformers. I'd like to see an argument
describing the benefits of using transformers vs the drawbacks
(including how much code would break).

-- Johan