@prescribingmum - I've been following Caroline Girvan for over 2 years and she has transformed my life. One thing I've done throughout is to intersperse her workouts with others, either to add more cardio (Growingannanas HIIT), or target my tummy/abs (Rebecca Louise's Best Abs plus some of Caroline's shorter, targeted abs sessions).
I do RL's Best Abs and the Bowflex 3-minute plank several times a week/almost daily and, together, they have made a huge difference to my form and tummy. A strong core feels sooooo empowering!
The iron series is serious stuff! If you are specifically looking for 30-minute workouts, I seem to remember the Heat serious being that kind of length. Also, I sometimes cut the longer EPIC 1-3 sessions in half and do them over 2 days. But only you can decide if you're ready for Iron!
I'd definitely go for CG vs a PT, particularly if it's a question of money. Maybe check in with your PT every 2-3 months for a tune-up? Caroline instills great discipline! If you're anything like me you'll get hooked and after a while you wouldn't dream of skiving off...😂