A very good point to raise!
Different studies seem to return different values for different kinds of rice, which really muddies the water here. Things are further complicated by the fact that 'basmati' rice can actually include a number of different strains of rice, though we can easily label them as 'white basmati' or 'brown basmati'.
For just one reference, take a look at the GI values for different rices in this study (if you're able to access the full text);
Broadly speaking the pattern is that white basmati has a lower GI than brown basmati (50 vs 63), which itself does have a lower GI than 'stickier' rices. Long grain rices are even lower GI (47) than white basmati, likely due to the fibre in the former.
Significance here is somewhat subjective. My feeling is that, if you're going to eat rice, long-grain or basmati is a good choice. But my personal preference is usually to replace that rice with a much more significantly lower carb, such as lentils, which can have a GI as low as 27.
Of course, sometimes you just fancy rice. It's definitely worth considering the lower GI rices. Another little detail is that brown basmati actually has less carbohydrates available per 100g, so the same amount of this rice will spike blood sugar a little less than others.
And depending on your lifestyle, regular eating patterns, and relationship with food, sometimes there's something to be said for indulging in a lovely sticky, high-GI, risotto-style rice. If you're disciplined with diet 95% of the time then you earn the freedom to waver every once in a while, with minimal negative impact on health.
Hope that's some food for thought!