I love the S026. It's my favorite 3Ch heli.
Yes, I'm still flying all my tandems. I like the NE Twingo. It's a nice lightweight four channel heli. As far as I can tell, it's a direct competitor to the E-Flite Tandem Rescue. The Twingo and the Rescue are roughly the same size and weight and they both use a single servo for aileron but do not have a servo for elevator. The aileron performs exactly like any other 4 channel coaxial really only that the servo is at 90 degrees to the body of the heli I believe (I don't have my helicopter with me to look at right now though). Pitch is controlled by changing blade speed between the front and back shafts.
Both helicopters both have a very similar sized battery and have similar flight times (~5-6 minutes? I haven't timed them recently..) However, I do like the Twingo's battery plug much better than the E-flite battery plug since the former is larger and easier to insert into the helicopter. The recharge time is the same for both battery types (about 45-50 minutes on recommend charger settings).
The TX for the NE Twingo is the standard NE "gamepad" style of controller that you can mechanically switch between mode 1 and mode 2. On this issue, I much prefer flying the E-flite Rescue because I use my DX6i to fly it. Another complaint I have is that the throttle on the Twingo's controller is a bit touchy. I have a harder time hovering the Twingo at a fixed height than I do with the Rescue. In fact, the E-flite Rescue has no such issues and hovers hands-free at any altitude. Also, as the Twingo battery runs out of charge, its ability to pitch will be greatly hampered. The Twingo has the same LVC behavior "landing" behavior as the other mcx (and I suppose the other NE) coaxials.
The Twingo is a Chinook like your S026 and S022 while the E-flite Rescue is a Sea Knight. You can get the Twingo in both civilian yellow and green/brown camo. I have both canopies and manually installed the LEDs into the "extra" one so I can swap them out when I want a change in scenery.
In terms of FF and "acrobatics" (as much as a coaxial can) like piros or tail-in/nose-in "funnels" (once again I use that term VERY loosely with these tandems), both of these helis fly well. They're not as good at FF as the single shaft coaxials but I don't care. There's simply something that I LOVE about tandems. I think it's because they're a bit more challenging to maneuver around than the other helis. It's a different kind of flying.
I've crashed both the Twingo and Rescue multiple times and have never broken anything. Their landing gear are flexible wires so it acts like a spring if you crash. The blades on both helicopters are fixed (e.g. don't pivot) but once again I've never broken anything. I was learning to fly 4 channels on my Rescue (and mcx2) and I put it through a bit more abuse than I would have liked. I think the Twingo could take the same kind of abuse and not have problems.
Of my four Tandems, I'd highly recommend the Twingo and Eflite Rescue over the other two in terms of their ease of control. I've never owned a S022 (unfortunately) so I can't comment there. In contrast, the Esky Tandem and the Walkera YS8001 are MUCH more powerful and challenging to fly. Those two helis use servos to control elevator AND aileron. I believe that this is the main reason why they are more difficult to fly. Even after adjusting the servo arms and giving it full trim, I still have to "balance" my elevator stick with my Esky Tandem to get them to hover. You can't just hover hands-free. You have to continually fly both of those helicopters. The Walkera has only been flown once but I've encountered the same issue with needing to balance the elevator stick rather than letting it sit at neutral position.
In terms of crash-resistance, the Esky Tandem is very fragile and will chip/split blades if they hit anything (including each other). The ends of the Esky's flybars will also chip really easily which will cause vibrations due to the imbalanced weight (I believe). The Walkera seems stronger as it's mostly metal (save for the blades) but I haven't had it as long though so time will tell. The fuselage of the Walkera is also quite fragile and will crack if you crash. It's easily fixed with a CA patch but you have to be careful. All of the other 3 tandems have much more flexible plastic canopies that will bend but not crack like the Walkera.
That being said, the ESky and Walkera Tandems are great if you can get them outside or in a big area like a gym. They really do want to move in big spaces and so it's hard to fly them comfortably indoors. The Rescue and Twingo work fine in either environment. However, all of these helis cannot handle any wind and the tandems have nice big cross sections that can catch the wind and send them flying.