Im in the same boat
Logitech G510S has been my main keyboard for a short while, coupled with the G502 Mouse.
I bought the G.Skill 780 keyboard and Mouse from the MM about a year ago and after a play, I decided to keep to the Logitechs and about 3 or 4 months ago, I swapped to the GSkills so I could strip the Logitech down and give it a full clean and then like an idiot, I borrowed it to a mate, who then "Lost it" - Now an ex-mate cos I know he sold it for a tenner.
I have been using the GSKills and to be honest, I am not 100% happy. The number of times the full stop appears is ridiculous! - I cannot have one, I seem to press it 5 or 6 times ??? The mouse took some getting used to, and again, thats not the best mouse either, certainly not on par with the Logitechs. The single worst thing with the GSkill keyboard for me, is the Macros... I liked macros in certain games and the Logitech was flawless in how is swapped profiles for any games I play...... ( see, I only wanted one full stop ), and I have a disabled hand and so setting up Macros for the few games I can still play is important to me.
I recently grabbed hold of a MadCatz S.T.R.I.K.E 5 as my mate has been raving about his, and setting up Macros are nice and easy ( Not as good as Logitech, but, still good ) and I am wanting to give it a shot, but it does not fit well under the monitor stand, so I need to do some work on that.
Im looking however, and I have NOT tried Corsair, but I do have a corsair mouse that I use with my Windows Laptop and its great, if basic.