Excellent posts and a plethora of truth.
On a scale of 1 to 10 concerning the importance of the micpre in the chain , it runs in the +6 department. Room, arrangement, operator skill set, song quality,high grade mics,all sit much higher and will always have a much more profound effect on the outcome of a recording.
That being said, with the gear list Max has provided and looking to the upcoming sessions he listed, there is a high probability that this new musical direction , with the girl vocals and the cleaner guitars, that a high-end pre WILL make an obvious contribution.
And there certainly is a LOT of em. My experience with the 'good' stuff has been that the pieces with a variable impedance on the input have a wider range of colors to choose from with a wider range of mics. The ViPre,
The Presonus ADL600, are examples.
What I'm getting at, is IF you have enough stuff to record decent tracks for most sources, then a couple of high-end channels is the ticket. BUT unless you have a KILLER mic locker, its best to choose something that has a bit of variety and options to it.
IMHO, you get more mileage out of a purchase this way.
In your case, Max, I would think seriously about a go-to mic at this time. A Soundelux U195 is going to really kick some serious ass in comparison to what you hear now...and this is only one choice. There are several out there now in this price range that will do magical things to ordinary set-ups.