I have used both standard 510 cartos, and 510 LR cartos on my 3.7V battery mod device. The eGo has a voltage bucking circuit in it limiting it ti ~3.2V. In my experience; the regular cartos, even at 3.7V, don't produce very significant vapor (it's functional and acceptable, but nothing fantastic)... The LR cartos can really make a dent in some
juice and produce some plumes. Some people use LR atty/cartos on the eGo, but there seems to be an increased risk of over-heating and damaging the MOSFET in the bucking circuit, (rendering it useless unless you are handy with a soldering iron and know what part to order).
The spinning method is a bit misleading because it depends on the viscosity of the
juice you are working with (which is dependent on VG/PG/H2O balance and temperature). Really, the "trick" to the "spin" method is not to worry about the spinning. More importantly, you want to "scrape" the drips off of the tip of the bottle of juice onto the interior of the carto tube wall such that the juice runs down the side of the can and comes into contact with the polyfill around the perimeter of the carto. When performed correctly, you can maximize the amount of juice that wicks its way into the reservoir (polyfill) while minimizing the amount of fluid that just flows down through the center and out the bottom. This is performed with the "tip" removed fromthe carto. The condom trick also works best if you remove the tip, so that you can allow some juice to pool up on top of the material; Followed by leaving it sit awhile with the condom still in place (vertically) so that the juice has a chance to absorb into the wadding.
Eric