Apples bands are a bargain compared to the watch bands from many traditional manufacturers. Price a Panerai leather band. Or try to buy a link band from Hublot. Tag-Heuer Link bracelets will set you back well over a grand. A Breitling 7-link bracelet is in the range of $1300 (a personal favorite)
I've been a "watch guy" forever. I own about 2 dozen different brands. I think Apple did a splendid job with their selections. The fluoropolymer rubber straps are among the best I've seen (for comparison, just check out the IWC rubber straps, or the Hubulot Big Bang at twice the cost of Apple; the Apple band is superior to both. The Milanese loop is wonderfully woven.
The classic leather is one of my 2 favorites. Just the right thickness, and the correct suppleness (not to soft; not to stiff). My one complaint is the "modern" buckles are finicky. Hard to align and snap together with one hand. I bought a replacement leather band for a Seiko Spring Drive a few years back. $400, and about equal to the Apple leather band, though the Apple classic buckle is nicer.
Finally, the link bracelets. This is bread-and-butter modern watch design. I think Apple's effort is mostly a success. The butterfly deployment looks good, and is well designed. It sits flush with the back of the links, a very nice touch you don't find on many butterfly designs. I was able to get it on and off with one hand easily. My one concern is the links themselves have pretty thin edges. They overlap, to give a continuous visual look, but those thin edges will be prone to knicks and bending. Apple's price for the link bracelet is actually pretty good; other high-end link bracelets can cost 2x to 5x more than what Apple is charging.
All that said, my wife and I ordered 2: 38mm SS w/classic leather buckle, and 42mm Space Black Link SS