Looks like you got a good result. I see you're not sure about the clean break, and all that. Personally, I would suggest you search the forum and read about the floc method. It's a pretty simple technique, and the short version of why, is this. Basically, everytime you make a cheese the milk is different (different time of year, different cows, different feed, different pasturization technique, etc). How your rennet and starters work with the milk will, therefore, also bit a bit different. So, rather than waiting for a set amount of time , which implies the rennet/starter/milk combo is always working the same way, and checking for a clean break, which is a bit subjective anyway, you time the effects of the rennet on your milk.
At the time you add your rennet, note the time exactly (i.e. to the second; I usually wait for the time to read :00 seconds to make it easy). Stir your rennet in as per usual, but then place on top of the milk a small plastic container (i.e. an individual serve yogurt cup - sterilized of course). give it a light tap, and it will sail around the surface of the milk. Every couple minutes, tap it and see what it does. Eventually, as the rennet starts to thicken the milk, it won't sail quite so freely. Now, tap every minute. It will start to just shift and stop. Check every 30 seconds, until you find the point in time when a light tap won't move the cup. It just lurches a bit, but gets hauled back into place, like a cartoon character with their feet in acme glue. When that happens, write down the time, and we call this the "floc time".
You are aiming to achieve a floc time of 10 to 15 minutes. If it takes less than 10 minutes, then use less rennet next time. If it takes more than 15, you could stand to use a bit more.
For our examle, let's say it required 12 minutes to achieve flocculation. Now, for gouda, you use a 3x multiplier, which just means multiply that 12 by 3 and you get 36 minutes. So, you cut the curds at 36 minutes post rennet (not 36 minutes from floc, but 36 minutes from when you put the rennet in; floc is at the 1x mark - so you're already 12 minutes into it and just need to wait another 24 minutes). At the calculated time you just cut the curds. Don't worry about clean breaks, just cut. See, if your rennet was working a bit more vigorously this time you might get a floc of 11 minutes, and cut at 33.
Higher floc multipliers generally lead to a moister curd and shorter mutliplers generally lead to drier curds. If you are sure you're going to long age a cheese, you might drop the multiplier a bit (i.e. 2.75x rather than 3x) and so forth. There are tables people have put on the boards suggesting what multipliers to use for different types of cheese, but remember, these are starting points. Adjust them to suit your tastes. I've posted an excel book (cheesetools.xls) which has a page on it that is quite useful for determing the different times when using the floc method, and it can be found in the library on the site.
Anyway, it's not really hard to do, and if you search the boards you'll find more detailed explanations about why this works and why it is a good thing to get used to. Of course, there are also a lot of people who go by clean break and they produce very good cheeses, so, it's not like it's manditory. I like it, but I like this kind of thing.