For those wondering, let's be clear:
No new VTC4/5s are able to be sourced at this time. End of story.
Most reputable dealers will now have this stated on their website so this confusion is further avoided.
If you are ordering from "joeschmoe vape site" and they have new VTC5s in stock, I call BS. Just accept that they are gone for now and move on for fugs sake....
There are still VTC4s floating around as NOS (New Old Stock). If the Xtar re-wrapped batteries are VTC4s: what they have is all they have and was sourced earlier in 2014, and when they're gone, they're gone. It is entirely possible that Xtar resourced the Sony cells for this particular line and could have button tops on them too. Xtar isn't exactly a whack company, though I frankly wouldn't put anything past anybody. I'd wait for someone to order a batch and test them properly with proper gear for temperature/discharge data to confirm. (and no, that doesn't mean your buddy with a 120W mod, it means a guy with probes and measuring instruments)
Batteries to replace the Sony VTC5:
LG 18650HE2 (Efest purple 35A is this exact same battery) (20A continuous)
Samsung 20R or 25R (20A continuous)
Orbtronics SX30 (30A continuous) (note: this could be a re-wrapped NOS Sony VTC4 as well)
AW 1600mAh (NOT the 2000mAh) (24A continuous)
The LG and Sony are available as flat tops or button tops. The Orbtronic and AW are button top only.
If you want slightly higher mAh for regulated devices below 30Watts:
Panasonic NCR18659PF 2900mAh (available at Orbtronics) (10A continuous)
Above all: DO NOT BUY BATTERIES FROM EBAY OR AMAZON. EVER.
Some reputable dealers:
Batteries - RTD vapor
Batteries - Batteries, Chargers, and PowerPax Carriers
Batteries - Lithium, Li-Ion, IMR, NiMH, Alkaline; Battery Chargers; Battery Carriers
18650 Li-ion Batteries and Quick Chargers
Edit to add:
I'm not sure on the Xtars, but the Orbtronic SX30 has always been confirmed to be longer than any other 18650 battery, and frankly just won't fit in some mods because of that. That could be that a re-wrapped Sony VTC4 with a button top added is longer. I'd look for the exact same problem with the Xtars if both are indeed re-wrapped NOS Sony VTC4s.