My 2 cents:
I use synths ALOT for recording, I freaking love them. I bought a Korg Triton LE about a year ago but it sits under the bed gathering dust (about to go on the bay)...it did everything except 1 thing well IMO. That's a bit harsh, but what it did do well is not worth me keeping it for.
What works best in the studio is to hook up an ordinary, even dirt cheap, keyboard (your controller, or
midi controller) to the DAW....in my case Logic - and use all the synth sounds from the built-in patches and manipulate the sounds and frequencies at will (I tend to avoid "real" sounds like strings and horns except drums).
If you are in a band situation or do not use computer based recording then by all means get a used Triton LE off the bay....but the LE tends to have hundreds of sounds and effects, most of them useless imho. I recommend you get something that actually specialises in synth sounds, not a "jack of all trades" keyboard....that's where I went wrong, anyway.
Get something specific not generic. Rather be limited by the synth than have a plethora of virtual instruments which, by the time you're going through them to choose one you are half falling asleep (like "oh, that sounds nice, oh that's quite nice, too...oh that's quite cool....oh, ha ha, that sounds like star trek, ha ha... ") One hundred patches later and you still have not found the sound you're looking for.
My advice when working with synths is to have a limit on your options (because remember, each sound is customisable).
But if you do want a keyboard that will handle your drums, strings, the odd vintage-ey synth, the freaky cow-bell, the robotic angel choir etc etc AND you do not use a DAW then you need a "jack of all trades" keyboard like a Korg or Yamaha.
