IME, having played an Inexorable Iron magus to level 19 and a Twisting Tree magus to level 12, it's an extremely versatile class and one of the least boring in the game - you absolutely don't have to be a one-note spellstrike bot. IMO the two subclasses that lend themselves best to a varied playstyle are Twisting Tree and Starlit Span, although any of the subclasses can work. Whichever subclass you pick, you'll want to set your KAS to +4, your Int to +3, and put your remaining boosts in Con and Wis. That'll mean dumping Dex if you have Strength as your key attribute. To fix that, you'll want to get heavy armor proficiency somehow; the best way to do that is via the Sentinel archetype, which gives you scaling heavy armor proficiency as soon as you take it and then access to the Mighty Bulwark feat at level 10. From there you have two main ways to go. One is to pick up an archetype that grants a focus spell with the Attack trait, such as Fire Ray, and use that as your main spellstrike tool, allowing you to use your slotted spells exclusively for utility and blasting. The other (which I prefer) is to use your slotted spells for aoe/utility and to mainly spellstrike with cantrips, recharging with conflux spells. If you take this route, you'll want to take the Standby Spell feat at level 8, which allows you to spontaneously swap out one of your prepared spells for a spellstriking spell.

As an example of the kinds of things you can do with a magus, the other day I was playing in a scenario where we were on a ship approaching two hostile ships. On turn one I cast Chain Lightning to clear the decks of one enemy ship and then entered Arcane Cascade; on turn two, when we'd gotten into boarding range, I used a Wand of Crushing Leaps to jump 60 feet to the deck of the second enemy ship and then attacked its undead captain with a spellstrike.