I have one customer with IWS and although the original designer made a mess of it, it works well and I was able to get excellent help when i cleaned up a little bit of it.
AFAICT, Maple Systems is nothing but rebranded stuff. Their larger HMIs are Weintek, and their newer HMCs are Renu. I made the mistake of buying HMCs from them (which aren't good to begin with), and tech support knew so little about them a project was delayed for months. When we finally found out we could go to Renu directly, the issue was resolved in a day.
Also, +1 for:
Red Lion (really nice)
IDEC (okay, good value)
Used the Maples (both Weintek and Renu), can only recommend the Weintek. Good value, but not very polished.
If we can afford to go rolls royce we use Red Lion, otherwise IDEC is the default.
Prices are low, but so is Automation Direct.
The HMI software is basic, covers most needs. So is AutomationDirect.
If you need a basic HMI, will engineer once, and ship out a 100 each year then either of those seem fine.
Need more umph? Red Lion is very good and easy to learn.
Need every feature imaginable? Proface is also good, but difficult to learn/use.
Want modern programming at any price? Beijer.