Well there's one thing to consider. Swingweight is basically a measure for the moment of inertia of a racket, with respect to a rotation. However, you always determine a rotational moment of inertia with respect to some fixed location. Now, if I understood correctly, while measuring the "swingweight", the axis of rotation is fixed at the handle of the racket. So "swingweight" tells you something about how difficult it is to move the racket with respect to you lower arm (effectively, the wrist is your point of rotation).

This is only part of "how heavy the racket feels" when you swing it, because there is another axis of rotation, that being your shoulder (your elbow could be considered one as well, even further complicating the picture, so let's ignore the elbow joint for now). And this is not taken into account by "swingweight"

So specifically, in your case, lemme try and explain why the radical still feels "heavier to swing":

The I.Radical (according to TW stats):

balance point : 34 cm

Weight: 306 gr (You posted 297, and I think this is why the difference in "swingfeel" is larger than you expect, but I'll explain later).

The Wilson HH 6.2

balance point: 37 cm

Weight: 278 grams

Now assuming your arm is 65 cm long and you hold the racket in a straight line from your arm (of course, this is not how you would actually hold it etc., but for ease of calculation let's assume).

The moment of inertia for the Radical would be (ignoring that of your arm, which is constant for both cases, and since the moments are additive of the racket and arm are additive, we are allowed to ignore it when comparing rackets) :

0.306 * (0.65+0.34)^2=0.299 kg*m^2

For the HH 6.2 :

0.278 * (0.65+0.37)^2 =0.289 kg*m^2

You see: the moment of inertia of the radical with respect to your shoulder is HIGHER than that of the HH 6.2. In other words, it feels heavier to swing (around your shoulder).

If we calculate the moment of inertia around the handle:

Radical: 0.306*0.34^2=0.0354 kg*m^2

HH 6.2: 0.278*0.37^2=0.0381 kg*m^2

And this is what is reflected by "swingweight": the moment of inertia of the HH 6.2 around the handle is higher.

In this case, apparently the effect moment of inertia with respect to the shoulder is more important than the moment of inertia around your wrist (which is indicated by swingweight). So the Radical is easier to "whip" around with your wrist, but more difficult to get into motion as a whole.

Which of these effects is more determining to the "swingfeel" is probably a subjective thing, depending on strength etc.... It also depends on the how big the differences in total weight and in "swingweight" are. For equally heavy rackets, of course, swingweight will be the determining factor in which one feels more heavy. For equally "swingweighted'" rackets, the overal weight (and the balance point) will be determining, and all situations in between can occur.......

I hope this rambling post gives you some insight into the whole thing. Oh btw, I am by no means claiming to have presented a complete model here ( I also ignored the elbow etc. etc.) but I think this illustrates that swingweight alone doesn't tell the whole story, and that this gave some insight into why that is so......

I hope most of you didnt quit reading halfway

..........

Hmmmmmmmmmmmm after reading my post again, my self-esteem got quite a battering..........I'm a tennisplaying nerd......quite a harsh thing to realise..........

Anyways,

Regards