Personally, I wouldn't be inclined to touch any qualification other than the C&G2357, even if at this point you can only do the knowledge unit elements of the course until you can get some sort of employment in the industry. I keep hearing from people who have Part P (EAL Domestic Installer Level 2), 17th Edition, PAT test (C&G2377), Inspection and Test (C&G2392) and some form of basic electrics course all at the cost of a small hatchback and no one will touch them.
You can ask yourself the main reasons why they can't get employment doing these courses but here're some to get you going:
1) No real world experience
2) In a recession when works tight and employees a plenty, would you pick a time served apprentice/mature trainee who has done at least 3-4 years at college whilst working on the tools or someone who has done a 4 week course at a training provider?
3) No ECS Gold card
I am sorry if that comes across negative towards the providers that offer these courses, and of course, individually, each course has its merit (even the EAL one that was originally designed for "allied" trades but was hijacked by the get qualified quick crew).
Having said all of that, I would be very happy to also hear about credible stories from people who have taken these courses, it would enable me to be a bit more accurate with my own work.