Teenage Engineering also makes a little device called the PO-33, which gives you the sampling capability of the OP-1 in a much smaller (and much cheaper) form factor. Check it out if this stuff interests you.
I had a bunch of pocket operators so don't get me wrong they're neat devices and an interesting start into music and sequencing but overall I don't think it provides the same abilities
I do like my op-z although I wish it was built a little better and that the iPad app (or another function key) let you zoom in on The sequencer so you could do longer sequences in something other than live record.
Still an amazing device. I can sit down and have a sketch down in a few minutes which is something I could never say about my desktop daw
