I bought a monogram speedy b 30 last year and love it! I find I use the strap pretty often. But I can't bear to part with my classic Speedys. For some reason I prefer classic for the Azur speedy- it has less vachetta - I like to see that cream colored expanse of canvas.
I prefer the classic over the b only because the b seems to be constantly plagued by some sort of issue, whether it be hardware prematurely tarnishing or the leather wrinkling, whereas the original is still solid.
If having the strap is important to you then I would exchange. Personally I can't imagine owning a speedy without the strap. I like having the option to be able to wear it crossbody or on the shoulder whenever I want.
I would say it depends on whether you are a hand held girl or not. A speedy 35 is a roomy bag, and once you fill it up, the shoulders strap in the speedy b will come in useful. I personally prefer the bandolier version as its more functional and minimizes any chance of staining the beautiful vachetta handles.
The bandouliere strap is priceless to me and makes the bag actually functional! I highly recommend it. I don't think it detracts from the bag's appearance either, and I actually like those strips of leather on the sides.
... I have a classic speedy 30 mono and wish it was a speedy b BUT I do have a strap for it... If I could do it all over again, I would get a speedy b coz you can always take the strap off - options!!!
I have the speedy b 30 in damier and love it. Previously I had a regular speedy and sold it because hand carrying was a pain. I do think that the canvas on the regular speedy is thicker and better quality though, at least from the one I had 7 or so years ago.
After using my speedy b for a few weeks, I decided to use my regular speedy. I haven't used it since the fall and decided it needed some love. Honesty, I prefer my speedy b due to the strap. It was a little annoying having to carry the regular speedy in the crook of my arm and since I had some heavy things inside, it left marks on my inner arm. Although I do love the look of the regular speedy including the sag, the strap is SO much better and more comfortable. I don't think i will ever buy a regular speedy again.