I have not tried Instore. However, I recently switched our shop to Square Up. The began a new program that charges a flat rate of $275 per month. We were spending anywhere from 500 on a slow month to 800 on a busy. This has helped us out a lot. It's a very easy to use and set up system, can add multiple printers, has a pay with your phone feature and people love the signing the iPad. Funny the things customers get excited about. There are a few features that I'd love for them to add like split tenders and assigning ticket numbers, but there's ways around it. Plus Starbucks bought into Square. Say what you want about them, I usually do, but they do their homework so if they're using it, it's gotta have it's advantages.
We switched to Square register back in September and haven't looked back.
I tried it when it was OWN and I had nothing but issues. I like the looks of it in theory, but not sure what they have to back it up at the moment.
We just switched over to Shopkeep. It works great and has great features for reporting, inventory and simple/easy to learn for baristas. $98/mo and amazing support. They are really helpful and open every day to help. www.shopkeep.com