Xsysinfo also enables clearing of RAM and it tells you how much RAM you're actually using. BTW, one of the confusing aspects of this entire discussion is that Apple insists on referring to data storage capacity as "memory." (i.e. 16G, 32G, 64G) I suspect that is to make comparison between the iPad and other devices with more RAM confusing and difficult. As Twerppoet notes, the actual "memory" (in the conventional sense) or RAM in the iPad 2 is 512K (compared to 256K in the original iPad). That's still not much but because Apple severely limits true "multi-tasking" on the iPad (and iPhone), it suffices.
As far as the inconsistent behavior being "missed in development," I have no idea if that was actually the case, but I suspect it may not have been "missed." Rather, if it works at Apple as it does in many software development organizations, there may have been a disagreement between development teams as to their individual requirements. Rather than trying to sort out the conflicts between two development teams, Apple may just have decided to let each go their own way as long as the inconsistent behavior isn't noticeable to most users.
P.S. I think the most notorious example of this sort of thing is the long running conflict between Microsoft Outlook and Outlook Express. Two incompatible email clients with almost the same name. The conflicts between the two went on for years, much to to the confusion of users.
P.P.S. BTW, I've noticed much more "free" memory (according to Xsysinfo) since I upgraded from 4.3.5 to 5.0 and now to 5.0.1. Prior to the updates, I routinely reached a low of 5-10 mg of "free" memory. Since the update, it usually runs more than 100 mg. Though Apple doesn't talk about it, I think they improved memory handling significantly with iOS 5.
