I have been operating a Flycam for a couple of years and am currenlty planning to ugrade to a better quality rig such as a Zephyr. I would say that the flycam has been great from an affordability point of view, allowing me to get some on-set experience and practice operating to see if steadicam is 'for me' but without needing to make a large up front investment. I've recently been on a Tiffen workshop so can compare the rigs, and I would agree with Jarrett when he says you will be dissapointed moving from a Pilot to a Flycam. I would even suggest that the models you posted are actially not as capable as a Pilot so you would be having a significant 'downgrade' moving to one of those. Do you own the Pilot or are you borrowing it, and is this purchase for your first personal rig?
My flycam rig is a combination of a 5500 arm/vest which I originally purchased and a 7000 sled which I bought as an upgrade as the 5500 sled was fairly poor, along with a plate to mount 15mm rails to the top stage. I can actualy fly a Red Epic on this setup and it works 'reasonably' as long as you dont get too ambitious. One of the major differences between this rig and a 'proper' steadicam is the arm action. I was quite amazed at the 'iso-elastic' performance of the steadicam arms and how much better the isolation of the sled is becasue of this. The other major difference is build quality, with various parts of the flycam being a little 'sub par' haha, and the lack of certain adjustments.
If you are purchasing a rig for personal use, and for no/low budget productions I would say the more expensive flycams would do the job but be prepared for a drop in build quality and stabilisation effectiveness, otherwise scour the second hand listings and see what you can afford
ps So you can see what I've managed to achieve with my rig so far, here's my reel, all shot on my flycam and almost all on 5D mk2: vimeo.com/53004629