Ok, I'm now doing IMUK and IMWales, training was all going well until I picked up an achilles injury so running is now off limits for a few weeks although all seems ok with swim and bike. Bloody achilles injury means I can run a half marathon in decent time and then hobble for two days.
Can't wait for Tenby (last year was superb). For those wondering about food intake, I finished the marathon last year on coke and ritz biscuits. My food intake plan went well until the run and started to unravel during the 2nd and 3rd run loops when my body decided my mind was a moron (something my wife already knew apparently!)
I did the LCW 2012 on a road bike and IM Wales 2012 on a TT. Added 30 minutes to my time using the TT bike and within 10 miles wished I was back on the road bike.
I'm doing IMUK 2013 and tempted to do IM Wales again as well. If I do will definitely use road bike. To be fair though my TT bike experience was pretty limited, but with all the hills the road bike was just more comfortable to ride for me.
As always, it's what you're comfortable with and would recommend the LCW if only to get an idea of the course. A good weekend as well.
Good luck to those doing it, 2012 was an amazing event, support is fantastic especially at the end of the first bike loop and during the marathon sections in Tenby.