Glad you are enjoying the "liquid midrange", these speakers are very hard to beat in this particular category, unless you spend $,$$$'s.
"No toe in" will surely give you a very wide soundstage, I always thought these speakers should be set up only this way.
REL Strata does wonders to this little gem, I hope you do decide to go that route.
What vocal music are you listening to now?
You should listen to Diana Krall album "The look of love" on this as it sounds wonderful, especially S'Wonderful (Track 1). Let me recall from memory what sounds really good on them:
The Girl from Ipanema - Getz/Gilbarto
Most of Ella Fitzgerald
Making Music-Zakir Hussain
Most of Solo Piano Music
I am forgetting many but will come back and let you know