Not sure I'd pay the rrp for Sonik rods, before thoroughly checking them out in the flesh..... I bought some S6's reduced, which were previously their top end rod, before the Dominator X.... when they hit the shelves they were £200 a pop, not worth that imo, hell of a lot of glossy laquer over all the whippings, too much, looks as though they have tried to hide some dodgy whipping...... They do the job, but imo no better than a £70-£80 rod.... what I've noticed is that mid range rods are usually a price hike on budget rods and as such are eventually sold at a budget price when a newer model comes out........
Can't remember hearing anything bad about Greys rods (others may have)......
Given the choice, if I was buying , I would choose the G4's if I could get them at a decent price, or even G3's which are dirt cheap, this is based on the Sonik rods I have. But ideally I'd be saving for some decent rods, Century, Harrison, Free Spirit etc. Because in my mind, a mid range rod, is a budget rod with a higher price..... Just my op.... Good luck