I started with a North Skimfish, although it's technically not a surfboard it was a good initiation into strapless riding, real easy...Or at least as easy as learning to ride strapless gets - lol. Being so flat it isn't something you'd want to take in anything but knee high waves or so, but it's quite versatile and lots of fun in just about every other water condition > especially in flat water. It's also my board of choice in marginal wind conditions, planing in some very light winds. Being more of skimboard, it can be a bit skittish (aka - like being on ice) when riding it on it's flat, so it's no surfboard in this regard.
In light to medium winds - up to mid twenties, small waves, swell riding, and even flat water, I use an Airush Cypher 5'6 @ 72 kg bodyweight. Like the Skimfish, it's a bit on the wider side so it's easier to start with being more stable in transitions and all. The Cypher planes quickly, smooth (in chop), controllable, carves a nice turn, has a nice snap to it, and is my all around directional board. Like the Nugget, it's just an easy to ride all around board. I've ridden it both strapped and strapless; I prefer it strapless unless it's windy/choppy and or bigger waves. Straps give me that extra control that's sometimes necessary, but you sacrifice "freedom" of movement on the board.
All said, you're an intermediate so nearly any kite surfboard will do. And, you'll get the hang of riding almost any surfboard quite quickly.
Note the twin tip like configuration on the Skimfish. During transitions, since I don't have my foot switches wired one-hundred percent of the time, I sometimes "cheat" and do a sliding turn and ride the board backwards. It rides either way quite well interestingly enough. The nose has a scoop, so when you ride the board backwards it simulates tail rocker. This smoothes the board a bit when it's choppy.
My friend has the Nugget and likes it in light to med winds and small waves. Like the Cypher, when it gets windy or bigger surf, it can work (you just have to slow things down to maintain control of the board) but it's not ideal. He uses the North Wam for that. I rode his Wam. That's a nice board as well! It's just not as efficient in lighter conditions and or smaller (less powerful) waves, as the Nugget or Cypher.
It's a matter of what conditions you intend to ride in. If you're leaning more toward more heavy surf and or higher winds, then something narrower with a bit less flat / a little more rocker is a good choice (not too much rocker however - too much loses versatility for anything but surf) > Example: North Wam, Naish Global, etc. From what I've tried there's no real "bad" boards per se'. Again, it's a matter of what range of conditions you want it for. Example > I'm looking into buying a smaller Naish Global to use as my high wind "bump & jump" board.
And yes, the Nugget is good choice for all around use. Like most boards in this size category, you'll be amazed at how well they get going @ 12 knots (I can easily get going on a 12 meter & Cypher surfboard / ripping upwind no problem) but can handle well up in to the twenties. It beats going back and forth on a giant door sized twin tip.