Since you've owned the SF for so long I'd expect your ears/brain to prefer the SF sound and other brands you try might sound different or exciting but after extended listening you'll find the sonic differences to be flaws, so I vote you stay with the brand you've been enjoying and go up the line. Bigger sound, less compromises with the same attributes that attracted you to the brand in the first place.
Large speaker recommendation
I've lived with the Sonus faber Elipsa speakers for 10+ years. Now thinking about upgrading to something with a bigger sound. Elipsa sounds great with classical music but not so great with pop/percussion type of music in my system/room. I do listen to classical music most of the time though, but hope to get a pair of speakers that are good in both worlds. Have also owned Tekton DI and Audio Solutions Figaro XL (really big, too big) but looking for something better, under $30k used or new, aesthetically pleasing. My system consists of: Mark Levinson No. 33H monos, Mark Levinson No. 523 preamp, Aesthetix Io signature phonostage, Basis Ovasion turntable, Vyger Atlantis turntable, digital components include Okto Dac8 Stereo, Oppo UDP-205, AMR DP-777 dac, Schiit Yggdrasil, and Bryston BDA 3.14. Room dimensions: 20x15x9 ft. Thanks! Ron