Yes, I use that system.
Previous printer was also HP, but before this arrangement came in. My new printer came with (I think,) 5 months free after which I started paying the monthly sub. So far, no problems.
Before I signed up, I costed the price of a single print, using the estimated copies per cartridge as a guide. At that time, it was way cheaper to use the subscription method, rather than buy cartridges when they ran out.
If it doesn't work out for you, you can always cancel and go back to buying cartridges when you need to, but I know which method I prefer!
FS