OK, Roose, here's a serious response that may actually help you. I owned the 3.6s for 6 months and ran them in a room 16X25 (about 1/4 of your space, I think, but my experience may still be appropriate for you). I bought them new, and during the first month I had reservations exactly like yours. I tried a decent subwoofer (REL Stadium) but found it dirtied up the midrange a bit and changed, but did not improve, the character of the bass. (This has always been my complaint about using subwoofers with full-range speakers, feel free to think I'm nuts if you want). I got a selection of resistors from the dealer ranging from 1 to 5 ohms. This helped with the brightness issue, and it can be fun to play with different values and jumper wires. Amps ranged from Belles 150 to Sim W-10s (1250wpc into 4 ohms). While I agree with many of the comments regarding the need for high wattage/current, I think your 250i, with 250wpc into 4 ohms and 30 amps peak current, should be sufficient for you to find out if you're really going to love these speakers. Three factors were most important in
getting me to love mine: (1)the Maggies broke in over 30 days, (2)my ears broke in (surprise!)in just about the same period--i.e. my frame of bass reference went from big, deep, somewhat bloaty cone bass to leaner, better defined panel bass that had shape and tonal color; and I became accustomed to, and welcomed, the pristine detail available from the remarkable Maggie high-frequency ribbon. As the days passed, I went from the 5 ohm resistor to the 2, the 1, and eventually none. Let's not forget (3) room placement: I found I was able to hear more bass by placing my chair closer to the back wall. You're at 3 feet now--try bringing it back to a foot or two. Bring the speakers much closer to you if the room arrangement/traffic flow allows--I bet they're getting swallowed up in that big room. I listened to my Maggies in a semi near-field position, with the speakers 10-12 feet away from my ears, and my ears about 2 feet from the back wall. Side walls are irrelevant in your case. Toe-in is most crucial to the tonal balance and of course tweeter position is too. Try putting the tweeters to the inside with extreme (45 degree) toe-in, and adjust back in 1-inch increments. Start with the speakers only 8 feet apart on center (this should fill the hole and "warm" the sound quite a bit. The idea here is to create your own little room inside the big room, but with the speakers facing in to the "room" instead of outward into your huge space, as others have suggested. You're mostly there already--I'm just suggesting you shrink the listening area a bit. Break-in of both speakers and ears, and demands of certain musical material, will probably have you adjusting speaker width and depth, flipping tweeter postion and diddling with resistors and jumpers as time goes on. All part of the audiophile fun.
My point is that the 3.6s can be fussy bastards, but they're worth it. I sold mine in a fit of audiophilia nervosa ("onward and upward!") but nothing I've had since then--all WAY more expensive, has given me as many goosebumps. I hope you don't give up on them too soon.