Reason has by far the best piano roll. It is very defined. There is no guess work. Either you want it to float or you click it to snap. Things never go where you don't want them. It's the smartest sequencer I've ever used. I record a section, press F8, then quanitize to whatever grid I want. Easy to select what you want. Easy to adjust clip size, easy to create additional note lanes, easy to do everything you want to do in a sequencer. If ProTools had a midi sequencer like the one in Reason I would have started making tracks in ProTools ages ago.
Midi is the front man in Reason. Analog style programming and patching is second. The only downfall is the lack of plugin support but there are only about 4 or 5 plugin instruments I need in Reason and only about 10 or so FX plugins I need.
If Reason had Nexus2, Virus TI integration, Nord Lead Emulation, and Ultra Analog with Softube PE-1C, Black76, White2A, Lexicon LXP, Soundtoys Radiator, Slate Digital VTM, Sonnox Eq, Maag EQ4, apQualizer, and NF Blue Tube Effect Pack I'd never need another D.A.W.
If ProTools had the seq from Reason with a Thor and NN-XT in plugin form I'd never switch to another D.A.W. also.