Which diameter suit my wrist better?

IMO the 35mm looks best. Beautiful watch 

35 for the win. 

35 hands down looks the best

35. But I generally prefer smaller watches. 

35 looks the best on you. 

35 looks ever so slightly better, but the 40 doesn't look bad. 

I find the 40mm too large for my 6.75“ wrist.  Otherwise, I think I would have bought one by now.  So I would say the 35mm is better for a smaller wrist.  

35mm looks superior. Why have an integrated bracelet when you'd need to do a wrist roll to appreciate it in the sun? 😉

35 mm

100% the 35mm looks much better proportioned on your wrist. 40mm looks too large. 

35mm

i think i am doing exactly as you suggest. i have an even smaller 6" wrist and i am waiting for the 35mm automatic

I'd say go for the 35mm. Also what do you mean it's coming out next year (unless you mean an automatic), it's already in stores.

35!

40 is a little big, but not too big.  Maybe it's just me, but my eye always focuses on the dial so if a case isn't ridiculously large, I don't tend to mind it being a bit big.

P.s. the smaller one in your case though given the choice but i think you need a 38 which isn't much help i know😂

If Casio can make sure the markers are hit on ~$50 watches, I'm sure Tissot can as well on watches that are more premium.

BTW the 35mm looks better on your wrist but the 40mm looks 👍 as well

I hope you aint casio salesman cuz you almost had me, that casio is lit 😂

but yes, i had the exact thought about the comfort issue with its lugs.

totally agree with you regarding the body ratio, I too felt like the 40mm might look abit toy ish on me and slightly too 'implicit/veiled?' with the 35mm. 

I'm heart for a 38mm as well, wish they have that as an option instead of a 40mm in the first place. I know many people hesitate in getting a PRX just like me bcz of its size.

I have a 6.5 inch wrist, and I purposely waited for the 35 mm. I'm glad I did.

My wrist is approximately 7 inches. Have the 35, 40 and 42 chronograph. I think all three watches work for me. For your wrist size, I think the 35 looks best. The watches were purchased in this order - 40, 42, 35. 

I find the 40 to be the least worn of the three, as I either gravitate to the incredible chronograph or the incredibly comfortable 35.

EDIT: I'd like to add the both the 35 and 40 are quartz, and the second hand hits the markers on both. So, second hand alignment appears to be inconsistent and it is the luck of the draw as to whether or not you get one that aligns.

You could pull off both but the 35mm looks just right.

I think both looks good on your wrist. But the 35mm is a sunburst blue dial where as 40mm is a waffle blue dial. You should get whichever watch that speaks to you more.
 

I love the blue dial of the 35 but I like both sizes for you , which ever one you go for make sure it's that sparkly blue and not the waffle dial.👍

I recently tried PRX, same as you want to get powermatic, but I think I'll wait for 35 powermatic version, have a 168mm wrist.

I'd go with the 40mm one. The Lug to Lug is still smaller than the width of your wrist. The 35mm looks too small even on your wrist. 

38-39 would probably be ideal ....

Go for the 35. The others are just too big for your thin wrist.

the 35mm is better and as you, I wait for the automatic version 

For people with thin wrists, go for the smaller PRX 

The 40mm wears bigger than what the size suggests because it is an integrated bracelet design