Try using a different 510 drip tip, I don't have any problems with gurgling and I suspect it is the Twisp drip tip with the smaller hole causing to much condensation allowing liquid drops to form in the mouthpiece, I had the same problem a year or so back with a device with a similar mouthpiece...
Something very interesting I discovered...on PBusardo's Ego One review, the Ego One battery tested a auto setting to 13 watt with a 1ohm coil....When I use the Ego One Tank with the 1ohm CLR coil on my iStick 30 I also found the sweet-spot setting to be 13 watt.
Will say it again...The Ego One...
a Few pictures for size comparison
Middle is a 2.5 ml tank
1100 Bat with 1.8 ml vs. 2200 with 2.5 ml
Evod 650 with Aero Tank and 30w iStick with Nano Tank
The Ego One is actually a variable Wattage/Voltage device that auto adjust according to the ohm coils used, if you use the 1.0 ohm coil this is a good device for beginners, at least to my opinion, look at PBusardo's review, this is a long review so you can skip to 35.40 to see the test...
At eCiggies you can get 1 x Ego One XL 2.5 ml tank and 2 x 1100 mah Batteries (the perfect combination) for R 1000.00
Remember to throw in a couple of CLR heads, they are brilliant
Any 510 Drip-tip fits the Ego One, but I think the one on the Twisp you will only get from Twisp...if they stock them.
eciggies also stock the CLR head, mine is on its way at the moment
http://eciggies.co.za/New_Stuff/eGo-ONE-CLR-COIL
Just buy them separate, this is an excellent device
http://eciggies.co.za/Dual-Coil-Clearomizers/eGo-ONE-Standard-CLEAROMIZER-1.8ml-1ohm-Coil
http://eciggies.co.za/Batteries/eGo-ONE-Standard-BATTERY-1100mAh
maybe we can also mention our very first purchase. Mine was this order from Walter at eCiggies, I used to smoke Dunhill Menthol at the stage
so I ordered Dunhill tobacco and menthol to mix, but the Dunhill smell was worse than my ashtray so I only used the Menthol and from that day I never used...