Hello all,
Since opting in 24 hours ago, I’ve experienced highs and lows.
I was excited to see the new feature arrive as I’m convinced that most of my patrons would prefer to pledge in their local currency.
I’m similarly convinced that many of my UK crowd haven’t pledged because they’ve previously felt railroaded into dollars and just don’t like it.
I was very disappointed to see that there would be a 2.5% conversion charge, which, as was pointed out further up, feels very steep on top of the 5% Patreon already deduct from our income.
I soon decided to swallow that bitter pill as I agree with Patreon that my increase in revenue will more than make up for it (which doesn’t mean that I approve of Patreon charging such a fat conversion rate).
When I did it, I then put out a message to all my Active patrons with the suggested wording in Patreon’s email. I also included my Declined patrons as I figured that might be a way to win some back.
The messaging process has been double-edged.
Firstly, I can’t stand the messaging feature. It’s incredibly clunky, confusing and full of traps.
This is the first time I’ve put out a message to all my patrons but I thought I’d take the plunge, particularly as Patreon assured me of this when I started writing:

BUT it transpires that’s not true!
Somebody replied to me.
So I replied to them.
Then I instantly received about 20 messages saying “I don’t think this is for me, Jack!”
Very embarrassing and thank goodness the message didn’t contain sensitive information.
So, I then had to put out another message apologising and it’s all taken up a huge amount of my day.
Why on earth does it work like that? And why is the typing field so small?
I’ve got so many other gripes with the messaging feature, but I’ll post that elsewhere… 
Back to the matter in hand…
Then I received lots of messages saying “my currency has been switched automatically” so I didn’t have to put the message out anyway…
…HOWEVER…
…I’m also glad that I did put out the message as many of my patrons are increasing their pledges!
They’re adjusting it to the same figure amount but in GBP rather than USD. To me, that’s a very useful insight into a patron’s mindset.
Today alone, my income has increased considerably because of the latter and that is good! 
I have already won back two declined patrons as well, so that is extra-good! 

Like @Funkybun, I’m slightly alarmed to see that my overall income figure appears to have dropped by some 25% but I’m assuming it might be a simple glitch — that the income figure is now actually sterling but still displaying a $ symbol instead of £. I do hope so!
In short, I’m pleased that Patreon are trying to give us so much of what we want but, sadly, it’s been fraught with difficulties for me.
It feels like the infrastructure (messaging in particular) isn’t properly in place and is too clunky to support major changes, particularly when communication is key.
I am very pleased that my income is increasing, though. Mind you, it feels like the increased income is merely covering my time dealing with the irritation and confusion! 
Sorry that this has been such a long reply — I had a lot more to say than I realised.
Best wishes to you all and I hope this helps in some way.
Keep on keeping’ on…
— Jack