Nektar wasn't a brand I was aware of until researching controllers, but I was impressed by the feature set, reviews, and price point of the LX61+. I've been very impressed and recommended it to my cousin - he's bought one and is also pleased.
The keys respond just as I'd expect a synth-type action to do - that may not be to everyone's taste, but it's just a question of what you're looking for.
I don't find the drum pads to be as expressive and responsive as I'd like them to be, so if that's the primary function for you I'd probably look elsewhere. They're fine, just not great (with the caveat that I'm not the world's best pad-drummer).
Once I'd realised that the driver (which comes with the unit) has to be installed for full integration, the LX61+ plays very well with Cubase, and the pots are easily assigned and responsive.
In short, this has been a great success - does exactly what I needed a controller to do, and does it reliably and competently. Highly recommend.