Shun Premier uses the same san-mai (three layer laminate) construction, with the same core alloy (VG-10) as Shun Classic. The only differences between the two lines are appearance and handles. Classic handles are straight "D" shaped, and either right or left-handed; while Premier handles are ambidextrous with an "ergonomic" curve.
For what it's worth, Shun Classic handles aren't exactly "wa;" even though they look like it. The Premier handles might as well be western. Either way, most western users find Shun handles very comfortable and have no trouble adapting.
The pattern welding on the Classic and "tsuchime" on the Premiere are non-functional, despite what Shun advertising would have you believe.
Shun knives are made to an extremely high level of fit and finish. They are very well supported by the factory and by their dealer network.
I hate the German profile they use for their chef's knives -- awkward, too much belly, tip too high, etc., but that doesn't mean you should.
Shun VG-10 knives are very chip prone when new, and settle down to being more chip prone than most over time. Steeling a Shun is always a little risky.
Masamoto VG and MAC Pro are both "single steel" knives (not laminated), and are made from "proprietary" alloys which are so similar they might as well be the same, and so much like VG-2, they might as well be VG-2. VG-2 is an excellent alloy; and probably better for your purposes than Shun's VG-10 because of its better toughness.
The Masamoto's profile is very Sabatier like -- which is awesome if you like Sabatier (and I do); while the MAC's is typical French and very good, if not quite as sweet. But, the Masamoto is more flexible than most European knives and many western users new to Japanese made knives might find that disconcerting. The MAC is fairly stiff (and FWIW Shuns are stiff also).
The Masamoto is better cosmetically than the MAC, and while the F&F isn't quite up to Shun's standard it's still pretty darn good. The MAC's F&F is at the same level as Shun.
MAC has excellent factory support, but Masamoto's is pretty much non-existent. If you decide to buy a Masamoto make sure you buy from a retailer who won't forget you as soon as the credit card goes through.
The MAC and Masamoto are equally good although they have different strengths and weaknesses. Both are better than the Shun. If I were buying a mid-price, mass-produced, stainless, western-handled knife for myself I'd choose the Masamoto. If buying for almost anyone else, I'd choose the MAC. I would not buy a Shun Premier under any circumstances.
It's a very good sign that you asked about sharpening. Sharpening and maintenance are just as if not more important than the knife choice itself. After all, there are scads of good knives, but all knives get dull and any dull knife is a dull knife.
The best honing rod for the money is the Idahone Fine ceramic. I also like the DMT CS2 (ceramic); F. Dick Dickoron Packer's Steel; MAC Black (ceramic); and Victorinox "Polished" steel. I don't know what a "sharpening pad" is. If you mean "bench stone," we might want to explore other, easier to learn and use options.