I would also invest in a quality DI (assuming your church doesn't already have one). That can make quite a big difference in your sound through a system. It may not have been the expression system you didn't like, but the DI.
I have an L.R. Baggs Venue (DI/tuner) and I love it. I plugged in with a Radial J48 the other day and played a bit, then swapped it out for my L.R. Baggs just to see if it really made any difference. It sounded like a completely different guitar. I hadn't really done a side by side comparison since I got the Venue, but man is it worth every single penny!
I travel and play at many different churches, as well as my home church, and it's very important to me that my guitar sound almost the same everywhere I go (of course a $10k sound system won't produce the same sound as a $500K sound system, but you get the idea). The only way to do that is to bring your own DI.
'Grats on the new 814, I had one two guitars ago and loved it. I only sold it to go even deeper into the Taylor cave to grab a pricier gem...the cycle never ends, lol. The 814s have a ton of body, and are pretty much required for worship leaders now, haha.
Pics, please when you get it!