Are Wilson Sophia's more finicky about placement?

Theoretically exact placement to the millimeter is necessary, but that would require your head to be locked into place with the same precision. Take these requirements with a grain of salt.

Clear your mind by having someone help you do a blind test. Set up your current speakers precisely. Listen. Have your helper move, or not move, the speakers without your knowledge, eyes closed. Listen again, repeat as many times as needed to determine whether you can reliably hear a change. You might be surprised.

I have owned wilson wp 6's, 8's and now Maxx 2's. Yes they are a little finicky. But most speakers are. These are a little more so to get their best, but they'll still sound pretty good. The Sopia may be a lil more forgiving...

If you need to move them, put some marks on the floor or masking tape etc. If you like Wilsons (I do), they will be fine for you.

All that said, if you want every note of performance, the 1/2 does help...sometimes quite a bit.

The Wilson Sophia speakers shouldn't be any more finicky to set up than any other high-performance loudspeakers. The Wilson Audio Set-up Procedure (WASP) is more about finding the room boundaries and placing the speakers in a place that they don't interact with the room, the zone of neutrality. This procedure has more to do with the room than the speakers. That being said, if you want the maximum performance from these speakers, I would recommend applying this to your speaker position. Your Wilson dealer is obligated to do this setup upon purchase. You can place a little tape on the floor to mark this footprint. You should have no problems moving them from this spot when you need to. Just remember to place them in the same place before listening next time. BTW, please don't put caster wheels on your Wilsons. They will not reach anywhere near their potential sound by doing so. Wilson only uses casters to help in moving larger speakers (MAXX2) when setting them up, after which the spikes replace the casters. Good luck.

moving 150lb speakers each time will not be fun and yes Wilson are more particular about placement then your current aerials or other typical speakers. Wilson speakers head designs and defraction panels are designed to prevent side wall interactions (aka like a monitor) so they don't throw as diffuse of a soundstage as most speakers do. Wilson Sophia's are more forgiving but WP's aren't.

I was in your situation and bought Magnepan's first(Get some 3.6's) and you can pull those out and put them up against the wall very easily.
If you have tile or wood floors and insist on the Sophia's get some Sound Anchor Cone Coasters (Stainless steel spike cups with a teflon pad that won't damage your floor and are large enough to cross tile gaps without letting the spike slip out). Get a T square or mount string on the wall so you can get the exact distance for the front left and right spikes. This would be a quick way to get that exact position. I use method with my Wilson Maxx II's and my WP7's before them when changing gear or cleaning. Leaving the Wilsons on the wheels doesn't sound good

www.riversaudio.com/files/spkr_plcmt.pdf do not have wilsons but this is great info on setting speaker position.