a tough question . . . .
Any of the risers will make a profound and immediate change in the ergonomics of riding a Spyder. My seating position and posture are changed radically. Steering effort and geometry is also completely different. This one change will made it seem that my footpegs, mirrors, seat and windshield are changed. Since these are ergonomic changes - the changes will be variable and personal - everyBody is different.
Brian (BJT) has posted that all the riser products have their pluses and minuses. Since they are the most common, I did get to feel how the NMN risers felt on a Spyder ( thanks, Repops!) before I decided to order. Like you, I wish I could have seen the other options in person.
I am (still) finishing my install of the 4" NoMagic risers on my SE5. One thing I can extrapolate to any of the risers is cable management will be the major pain of the installation. There seems to be a lot of variability in how the dealers route the cables when they assemble the Spyders. The cables and wiring probably all take the specified paths, but where the ties are, how tight the ties are, the order that the cables are layered and the order that they are connected (while all these are small differences) can make the installation a profanity laden experience. If I had it to do over again, I would do the 3" risers - the 4" seem to be right at the edge of cable tolerances. While they work, I know I don't have all the adjustment options that the 3" would allow. But I am still working on them. A wild guess is that the install on a SM5 would be easier than the SE5, but that is just a guess. The fit is OK and the finish is good. I (so far) am not crazy about how the workable cable routes looks on my SE5, but I think that is something I will adjust to and ignore.
The cable length issue is one that any riser will face and it seems to vary from Spyder to Spyder.
For me, I didn't like the look (especially the dislocated ignition) of the Heli Bars. Price didn't help either. But, that is my taste and wallet talking.
I think QuadManiac has a good point - the Spyder City 3" risers have a lot going for them. The install looks to be easy and the original Spyder looks are retained. What they lose is the adjustability factor, but I think he is right about the best bang for the buck. They come the closest to the BRP option, but avoid the difficult costly install. If I can't get the 4" NMN right, I will give these a shot.
My bottom line opinion is that all of them are quality products that will change the fundamental feel of your Spyder. Any 3" change will probably have an easier install and fewer cable issues. The Spyder City risers will do the job while keeping your wallet and the Spyder's looks intact. The NMN risers will give you the most adjustability.
If you still cannot decide, try and meet with other riders in your area ( or just passing through ) so you can see and feel them in person. ( Hey! this is a family site, keep your mind and hands on the risers! )
Tom