Well, the form at the Active-Domain site let you put in several domains to transfer all at one go, so I thought "hmmmmm...." I have one re-direct domain which has been at Register.com for ages and I have HATED those motherfuckers for years (ever since they sent out an e-mail offering all sorts of stuff, with a "more info" link that automatically registered three domains for you ... with my name in .com, .org, and .biz). I mean, sure, I might want to have those, but I have NO USE for them at the moment and it really pissed me off that they would have the gall to REGISTER them wthout MY PERMISSION (I was only clicking on a "more info" link!), and then bug the living shit out of me for expensive renewals once the "free registration" period was up. As I said ... I have HATED those motherfuckers ever since! Now, the domain I had at Register.com was one that I use ALL THE TIME and really don't want to mess up on, so I have been very hesitant to make any changes, but as I had JUST paid them for a new year (and Active-Domain credits you for time on your existing registrations), I figured I'd give that a shot too.
While this is all still in process, I am feeling so "free" to kiss off both Register.com and Network Solutions (at least I think that's my last thing at Network Solutions ... over the years I had several there). BOTH of them were all "oh, you're making a terrible mistake" and "oh, you need to sign off on our AGREEMENT" and shit on their forms, but from what I read at Active-Domain (and the instructions my ISP helpfully sent me) I don't think they can really do anything other than comply with my transfer order (especially since they're long-standing domains, they all seem to have blocks on moving something in its first 60 days).
So, cross your fingers for me that this all goes well ... also, if anybody has cautionary tales of trouble moving things away from either of these, please let me know, so I can be prepared to go to war with them!