ProAc Studio 100 vs. Proac 1SC vs. Harbeth P3ESR

There are a million threads on here about Proac vs Harbeth, etc. but I will go ahead and start one more. I will be revamping my system over the next year or two and am starting with new speakers. My preference is to use monitors with a sub. Listening tendencies are jazz, rock,and country but no classical or rap. I also plan to use SS amp and pre-amp.

Over the last few months I have listened to various monitors from Totem, B&W, PSB, and ProAc. Easily, my favorite to date are the Proac Studio 100's. I love the mid-range, purity, and detail present in these speakers. That being said, I have narrowed it down to 3 choices based on what I have heard and read. If I buy used, I won't have a chance to audition so I would really appreciate some general opinions on the 3 models above. Specifically:

1) Are there any major differences in sound between the Proac 1SC and the Studio 100s? If so, how do they differ?

2) Can anyone who has heard the Harbeth P3ESR make a comparison to either of these Proac models?

I know it's impossible to form an accurate opinion without hearing all 3 but any general comments would be valuable to me. I'm sure these are all good choices but hopefully I end up with the best one for me. Thanks.
I've heard the 100's in both demo rooms and recording studios - great speakers, but I have P3-ESR's. Honestly haven't heard the 100's in a while, but I just really dig Harbeth so that's what I'm into. From memory, I found the 100's a little too boxy - that's always a deal breaker for me...
My experience is only with the P3ESR and Proac Tablette 50 Signature.

From what I gather the Studio 100 is a lower-end model in comparison to the 1SC which used to be Proac's reference monitor. Although decent, the Studio 100 is not in the league of the 1SC in terms of poise and refinement. The 1SC will have superior separation, imaging and delicate highs, whereas the Studio 100 will sound as what Zkzp8 had described, though the bass will go deeper due to the larger cabinet and mid-bass driver. Between the Studio 100 and 1SC, I wager it's a choice of a bigger scale and fuller sound of the Studio 100, or a more refined and delicate sound of the 1SC.

Personally I would go with either the 1SC or P3ESR. The P3ESR will have the signature "organic bloom" of the Harbeth house sound which gives a warm glowing feel to music. The Studio 100 is not at the level of both these speakers though it may be able to play louder.

Since you find the Studio 100 an excellent speaker, you may want to consider it over the 1SC or P3ESR to minimize your risk if an audition can't be arranged.
The Studio 100 is still one of the best all around speakers in audio. Unless you go to a D2, you'll be splitting hairs.
Thanks for the responses. I appreciate hearing from people who have experience with these. I am not sure what I am going to do but I think I got some insight. I would love to hear the Harbeth but don't know if I will have that option. Thanks again.
I don't have much experience with any of the speakers you mentioned, so my advice should be taken with a grain of salt. I've heard them, but not for any length of time to give the insight the others here have...

If you're really intrigued by Harbeths, you should definitely make it a point to hear them. When I was speaker shopping, I heard a bunch of speakers. There were some excellent ones that I'd easily have been happy with. Something told me to track down Audio Physic. I'd almost made my mind up when I went to a dealer on the way back from another audition. Unbeknownst to me, he carried the speaker I was looking for. It was exactly what I was looking for in a speaker, and then some. I've happily had them for 4 years, and they blow the doors off everything I've heard anywhere near their price.

I'm not saying buy Audio Physics. I'm saying if you're truly interested in the Harbeths, find a way to hear them. Harbeths don't have a cult following for nothing. They're excellent speakers that I think everyone in this hobby should hear at least once.

ProAcs are excellent speakers as well. Keep in mind the best speaker will most likely be the one that fits your room and system best. If you have a bigger room, the Studio 100 may end up sounding better than the 1SC, even though the 1SC is a "better" speaker, lineup wise.