Smokescreen probably resembles his G1 counterpart the most out of any of the alternators - similar car, TF and robot mode, just with a little bit more complexity here and there. Important to remember that the legs need to vaguely resemble a rear seat once it's been transformed back to robot mode.
Sideswipe however is a complete departure from his G1 form in both car and robot forms. This is something of a departure and a bit hard to adjust to especially as I'm a long term fan of the original Sideswipe. Not my favourite Alternator.
Silverstreak is a repaint and minor remold of Smokescreen in the trademark lost Bluestreak silver colours. Nice job, but Smokescreen is the better of the 2.
Hound - like Smokescreen - benefits from looking like both his G1 vehicle and robot selves. The Transformation is surprisingly complex for something that looks to be so simple - I remember getting repeatedly stuck with the seats in the back of the vehicle hitting something mid TF. The suspension is lovely on the vehicle and it's all round a great toy.
Deadend: Hands up who remembers which Stunticon Deadend is ? No I didn't either, and when I checked he wasn't even the one I thought he was based on his appearance here ! But the Alternator version is a great toy - recently voted the Hub's favourite Alternator redeco. The Sideswipe mold gets a roof and a few other alterations as well as a superb black paint job which make this an very appealing toy to own, I'd say it was my favourite Alternator if it wasn't for ....
Tracks: lovely car and robot mode, both resembling the original character but with an enhanced robot form - love the wrist blasters. Fabulous, looks great, and Takara have even corrected their mistake with the colour on the original version.
Jazz is the first Alternator I bought that suffered from the plastic looking plasticy - see the separate Windcharger review - and this distracts me from the toy a fair bit. And unfortunately the white plastic in car mode is very visible in robot mode. I remember the legs being a complete nightmare to transform the first time I did it, odd things going on at the hips. And the arch behind the head was distracting me. Again not a favourite.
Grimlock & Windcharger are reviewed elsewhere. I don't own Swindle at the moment, and I don't think I'm impressed enough with him and the other Alt repaints (Grimlock as Wheeljack, Jazz as Shockwave or Track as Ravage) to buy them.