Having had experience with 123-reg I wouldn't recommend their service to anybody aside from someone who wants a cheap .co.uk.
Registered a domain with them last year and used their hosting "services" a couple of months later when I didn't have time to shop for deals (I was just hosting auction photos on the domain).
Noticed some annoying tactics like putting you through 3 registration pages and after that they THEN announce an extra £10 upfront "admin" fee even if you go for the cheapest "starter hosting" plan. They rave on about this plan's "amazing value" and SHOUT the monthly price minus vat (with tiny footnote - "exc vat")
Along with the insult of the unannounced £10 extra made up fee, they THEN announce 12 months minimum contract payable upfront etc.
I found the host performance to be very unreliable, especially at peak times. This obviously means they cram as many vhosts as they can with their resources!
Considering I was only hosting auction photo's these small, webready thumbnails were taking up to a minute to load and it was only after changing to their hosting!
The final straw was when I noticed bandwidth usage was approaching the limits. Looking at their extra temporary fees for topups I discovered for 100MB extra bandwidth, they charge their unfortunate customers £25 ($40 or more)..!
I very quickly started sourcing other solutions and soon after, transferred out and now I have far, far more for a fraction of the price!
Sometimes even the most "established" companies can really take advantage of their users and charge criminal amounts for simple services. An expensive lesson but it lead to far more knowledge on the real options out there... consider them!
stone-ranger