I’ve got 4 of them 
I’ve got The Premium, The X Pro40, The Starlet 2 and also The Inside Out.
The first 3 are actually very similar in how they feel and the way they do it for me, The Premium I would say is the most intense followed then by the X Pro40. But, the Womanizer Lovehoney X Pro40 doesn’t come with different size suction heads and that was a real issue for me - I wrote a bit of a topic on it here and how I solved the issue.
The Starlet also doesn’t come with different heads I don’t think but I only received it in the Christmas Advent Calendar so I’m unsure about that - it does however fit my clit perfectly and is still plenty powerful enough for me to cum in minutes.
Now, the Inside Out…. Wow. Something else all together. If you like to have something internal to clench around while reaching and during orgasms like I do, then this will blow your sole. It comes with different size heads and the suction pulses are insane. 