I'm also a fan of the DLX 8.3 TT slick, size/shape/steepness is perfect to me, the wheelbase is also good to me, even with Thunders, maybe I have wide hips or something or prefer the stability it adds? Maybe the shortish kicks paired with Thunders with forged plates help keep it snappy enough? Same board with the same wheels, I prefered the pop with Thunder Hollow Lights vs with Indy Forged Titanium, weight is similar but it feels quicker, snappier with the Thunders.
The advantage of slicks depend a lot where you skate I'd say, they don't change much in perfect smooth skatepark surfaces. It's when you get on rougher stuff that it helps, crusty ledges, stickier wood, less used spots... I remember having some in the early 90's and loved being able to slide almost anything but back then it added a lot more weight and they often peeled off and delaminated quickly but now they seem to hold up well, maybe even adding a bit of durability to boards? It still adds weight but not as much as back then... and now that I'm no longer an always broke kid, I can afford light trucks so I don't mind a few extra grams due to the slick.