Introduction I chose to learn Welsh for the pleasure of it, because I am familiar with the country from childhood holidays. I discovered SSiW on the Internet, tried it and liked it.
North or South? Doing both! Sounds a bit inefficient, but it’s actually good practice. As I’m likely to find myself in the North more often, I regard the North version as my main one. I do the South largely to become acquainted with the regional variations. I would probably use North in speech.
Courses or Levels? Started Course 1. About halfway through I discovered Level 1. So I finished Course 1 and then did Level 1. And I’m doing the same for Course/Level 2. They complement each other and effectively permit revision with fresh material. Yes, it takes time, but I need to go over material a lot anyway when learning a language: it’s the way they wired my brain.
You went through most of our material in three or four years Taking its time. Over 2 years to arrive halfway through Course 2. But I’m in no rush, and I learn at the speed I wish within my time limitations (like most of us, I have a job, family, other interests, life’s problems…). Otherwise I stop enjoying it.
Go through the lessons without repeating any Sometimes I can go through about 3 lessons straight without repeating. Usually I do North a couple of times and South once.
Not use the pause button Rarely use it. I learn whilst doing housework.
do the listening exercises Yes, and it makes a difference.
get a conversation partner I need to.
understand different accents No problem. I think that doing North and South helps here.
put off reading I’d like to start eventually.
accept all the different ways of saying the same thing Again, doing both versions helps.
avoid worrying about grammar I like a BIT of grammar. In its descriptive, rather than prescriptive, role.
getting used to saying R Probably sounds dreadful!
getting used to saying Ll I try! If you ever speak to me in Welsh, you may find yourself discretely wiping your face with a tissue 
…
getting used to saying Ch No problem. Familiar with it from the Scottish “Loch”, plus I speak Hebrew which uses the ‘ch’ sound a lot.
General observations:
I think that everyone should learn in his/her own way. No two people will ever learn the same way. So I regard the SSiW “rules” as guidance lines and not hard rules.
The one SSiW rule that I advise everyone NEVER to break is “Don’t Worry”. I can’t overemphasise this, and I frequently remind myself. It really helps.
The frequent encouragement at the beginning and end of the lessons is great and has a big psychological impact.
I need to chill out occasionally and go a few days without Welsh. I come back with a vengeance.
New material just will not sink in when I’m tired. Almost a waste of time for me. On several occasions I’ve done a lesson and felt like just quitting the whole damn thing. The next day, refreshed, I redo the lesson and it’s a whole new, positive experience, and the material really gets learned.
Every now and then I feel that I need to go over a lesson several times, with the pause button, to revise everything learned until then. It’s not a reflection on the difficulty of that particular lesson. It’s the need to revise the material accumulated at that point. Very good technique for me.
I frequently check a word in my Welsh dictionary if I’m not sure of the pronunciation.
What would I like to see that isn’t there?
Exercises translating from Welsh into English would probably help me tremendously.
A bit of grammar, as mentioned above.
Just last week I finished the final lesson, now I’ve moved on to the new challenges (still southern) and am up to challenge 8.
Me and the kids give a little cheer when we pass the ‘Croeso i gymru’ sign on the A40.
