I was stuck between the Obsession and FutanaX 100 as well but weight is always proportional to size so comparing the two on weight alone is not an not apples to apples comparison. I decided to crunch some numbers and thought I would post my findings.

The Obession is much larger (really a 27% size) than the Funtana 100X with 155 sq. in. more in wing area not to mention the larger span and length. The Obsession might be better compared to H9 27% Extra 260 ARF but the Obesssion is still lighter, bigger (especially in length), cheaper, and has 129 sq. in. more in wing area than the Extra 260. The FutanaX 100 example in Model Airplane News had a weight of 9.23lbs with a wing loading of 19.22 oz/sq. ft. At 10 lb the Funtana X 100 wing loading is 20.79/ sq. in. A 12lb Obsession would have a wing loading of 21.89oz/ sq. ft. I don't think I could tell the difference between the two unless I was at an expert level of skill. At 11.5 pounds that drops to 20.97 oz/sq. ft. A wing loading of roughly 24 oz/sq. in. at 13 lb is pretty darn good for a 27% airplane. There have been 11.5 lb versions of the Obsession and that was without replacing the aluminum wing tubes or LG with carbon fiber, lighter wheel, etc. so 11 lbs (20.07 oz/sq. in) might be possible with some work (hmmm...). The few I ask about the weight though say not to waste my time trying to lighten it up so that is a good sign. I did crunch some numbers for a better comparison of size and the H9 27% Extra 260 has a wing loading of 26.41oz sq/in at 13lb, which is notably (2.41 oz/sq. in.) higher than the Obession given that their Extra is 11 inches shorter.


My main concern with the Funtanax 100 is that knife edge is great with the SFG's but that assumes they survive "every" landing and transit to and from the field. I am leaning towards the Obesssion just because at 12 or 13 pounds it will still do everything without CFG's and the size and look are pretty impressive. That rudder is massive (roughly a foot). They did make some changes in design to the FutanaX wing to improve stall characteristics and high alpha. Also, to me the SFG's are a band-aid that addresses the knife edge ability versus fixing the overall design. That said, the downside to the Obesession is that engine selection/weight is more critical due to the narrow cowl and balancing, it is not legal for most competitions, and if you want a four stroke engine it is going to cost a lot more but you don't need a gasser. I also found it interesting that there is only a $60 difference between a Saito 125 and 180. For the power folks out there, there is only a $160 difference between a Saito 220 and 125. I only state this obvious info on the engine prices because with Towers current price of $220 on the Obsession, that is exactly $160 cheaper than the H9 27% Extra 260 ARF which covers the difference in the cost of the engines.

I think I just made my final decision. Obession and Saito 180 (or 220 if someone talks me into it) and eat the difference in what I will have to spend on larger servos which I can use in another plane down the road anyway. I think a 220 would be too much but if anyone feels different please speak up. The 220 weighs 7.5 oz more so balancing might be an issue but I could opt for two large rudder servos and move the battery back to help with that since it has spots for them. The 220 would be nice for a future plane but I am afraid flying around at 1/3 throttle wouldn't be any fun or as reliable. Also, a 20 inch prop on the Saito 220 is only going to leave about 1 inch of clearance (aggh!) John, what throttle setting are you at most of the time on the 180? What size prop? Is it mounted inverted? Just curious ! Thanks for the feedback on the 180 John. That helped with my decision.