I've had good luck with Target. My first two BN Classics that I ordered from them on November 6 are scheduled to be delivered today. But my Nina Simone - I Put a Spell on You is still on backorder. (It hasn't been canceled yet; I got my last accept-this-delay email this morning, and clicked the button.)
I've had a lot of delayed records through Target, but I only had one canceled: Bobby Hutcherson - The Kicker. I contacted customer support, and they told me to sign up on the item page to be notified when it was back in stock and to reach out to customer service again when I got an email. They honored the sale price. (I can't remember if they adjusted the price while it was in my cart or if I had to order it and they immediately refunded me the discount; either way, they took care of me through chat while I placed the order.) That was a bit of a pain, but I was glad they were so helpful.
I've also ordered too much from uDiscover. I've experienced the same long delays others have talked about, and dealing with their customer service is a very prolonged process as opposed to the live chat you can have with Target. Still, I've received every record I've ordered from them. And now that shipping is free, I always place preorders separately.
In the end, I've been pretty happy placing orders from both places. My first Tone Note purchase was Wayne Shorter from AcousticSounds for $34.99 (a little cheaper with a 10 percent off coupon, but still) back in March 2019. I thought it was amazing and was ready to start shelling out that much regularly. But now I buy most of them for about $20 through Target and uDiscover sales. I find I'm willing to pay more than that only for the ones at the very top of my list.