Hi! I have use a Novation 25 SL MKII, and while it's a little bit old now, it's really great for controlling Reason, particularly synths (built in and rack extensions) and effects. It requires some programming of the Automap templates (Automap is the software interface between the keyboard and Reason, the templates that come by default are a little disorganized, and have no rack extensions), but once you have them, its great.
It has 32 buttons with on-off status, 8 faders, 8 infinite encoders, 8 normal encoders, 8 velocity sensitive drum pads, a pith bend-mod joystick, and a xy touch pad. One row of 8 buttons also can work as transport. It has 1 screen that tells you the name and value of 8 controls at a time, and as soon as you touch a control it shows the names for that group (controls are touch sensitive). If you want, you can also see the funcion for each controller on the PC screen on the Automap software (there is a "View" button in the MKII for this). Buttons can be programmed on-off, or to step several values. In Reason, you can choose between controlling the mixer, or a device in the rack, and is easy to change tracks and presets.. For each device, you can have several "pages" of controls - e.g. page 1: Oscillators and envelopes, Page 2: Lfos and filters, etc.. (you cannot show a name for the pages though)
The Automap template editor is complete but lacks some basic functionality and is buggy (e.g. you cannot copy controls for one page to another, when you move controls within a same page you loose parameters, you cannot reorder pages, etc..), but you should only need to program each template once and then you are done - and there is a learn function that makes programming fast. (I programmed templates for the main Reason synths and some rack extensions which I'll upload on another thread when finished). For rack extensions, you'll need to add the device to the remotemap file using "Pot 1", "Pot 2", "Pot 3", etc.. (order doesn't matter) and then make all the template programming in the Automap editor (see here https://tonalaxis.wordpress.com/2014/01 ... s-automap/
- also note the Novation's site incorrectly states that you cannot control Rack extensions.. that's false!)
The SL MKII may not be as integrated to Reason as the Nektar series (e.g. you can't add devices from the keyboard), but in comparison with what I've seen (I don't own a Nektar), you can have direct access to more synth functions (without menus) from the SL MKII, and is easier to see what function corresponds to each button / slider / encoder (touch sensitive controls are great for this!). For the infinite encoders, it is also easier to see the current value of each one - you see it directly in the control. The SL MKII is also very good for controlling VSTs and other DAWs, and you have versions with more keys.
I currently use it with a Push 2 with Pusher, which is way better for controlling drum devices, and for general functions (add tracks, devices, etc...), and it's awesome - although it's somehow expensive for using only with Reason.