Isnt the stand sewn binding? If so then even if the book separates from the spine the actual pages will still remain intact with use because the pages are attached by thread and not glue. Well that is how I understood sewn binding to work.
We can expect Volume 16 of the ASM MMW to be released in TPB by February 2028. Each Masterwork volume contains around a year of comics and on average comics out every 18 months. The Epics contain a year and a half of comics and currently come out once a year. So in three years there will be two more years of ASM collected in the MMW TPBs and four and a half years of ASM collected in the Epics. The Epics definitely publish more but it's out of order.
Currently there are four Spider-Man Epics, Vol 1, Vol 15, Vol 20. Vol 22 comes out in 2015. Now, estimating roughly Vol 2-10 will cover the material currently covered by the Masterworks (which are up to #168). Thats nine volumes, or nine years. But there are also nine volumes spanning Vol 11-14, 16-19 and 21. So it could be eightenn years before that entire patch gets filled in, if one of the Volumes 2-10 is the last one released. But thats assumed Vol 22 is the last volume, which is highly unlikely.
At any rate, you're either looking to spend a lot of money on Masterworks or wait a while for the MMW TPBs and Epics. Now, had Marvel not screwed over the Epics and kept them on the accelerated two volumes per year schedule then it would be a no brainer, go for the Epics. But right now it's really hard to say what format you should go for. With the Masterworks TPBs you know you've got a 13.5 year wait, with the Epics it could be a shorter wait or a longer wait. Really it's up to you and it depends on how badly you want to read the material. For what it's worth I'm pretty sure all of the MMW'd material is on Marvel's Digital Unlimited service so if you just want to read the stories thats an option.