I had Robin Hood last year and their prices shot up so I switched.
Bulb don't seem too bad but their daily charges are high so the best savings are for those with high usage. As I read it:
Electricity: 12.35p/kw plus 24.56p/day
Gas: 2.50p/kw plus 24.56p/day
Dual fuel discount and of course £100 if using your referal. I've not done all the sums but £100 isn't to be sniffed at but my electricity usage from June to now is just cheaper with my current supplier.
For electricity I went with Powershop who have a reasonable rates but then a unique idea - they have regular offers for power, so for instance you can buy £10 of power for December with a 23% saving and I've just seen this weeks offer of £14.05 worth of electric for £8.82 - 37% discount. I've just about bought enough advance power at better than 20% savings to last till next summer! Switching referral isn't as generous - £25 each offer ends end of the year. They don't do gas for which I'm paying 2.62p/kw plus 20p/day with another supplier.
The main message however is that there are deals out there. I'd never switched* in 30+ years prior to two years ago and am sure I've saved quite a lot.
* well I had coal as well over that time and did switch merchants and ended up internet purchasing, for a while in 1 tonne pallets - big savings!