I am whizzing about on a Spesh Allez Elite Compact (this has the E5 frame and a Tiagra set rather than Sora [2012 will lose the E5 frame and gain a ring on the cassette; 2011 on silly, silly offer at
Evans). It's a great bike etc, etc, but I would hesitate to use it as a commuter because it is, as others say, geared up as a winter trainer and entry-level race bike. It's a ton of fun to ride, but it comes into its own when you push it on steep climbs and fast downhills. I use mine as a fitness bike. I'm a self-employed writer/consultant working from home, and use the bike to get some movement into my life that would otherwise revolve around the office and the kitchen. My routine is to bez out for a fast 8 miles every lunchtime. The Allez is utterly perfect for this.
But, it is a good commuter? You have a hybrid, so the ideal commuter bike space is covered. If you want fun and can afford it, then sure, go for the Allez, but understand that it's an unforgiving machine in its guise as a low-groupset, alu/carbon interpretation of the Tarmac. If I were you, I'd sure look at the Allez, but also take a look at the Secteur, which will definitely suit your long Bristol/Penzance run, and also handle long charity rides too, while being comfy enough for your turbo-charged commutes – the geometry is borrowed from the iconic Roubaix, and is arguably the best way to go.
But, here are my final words. For a bike to be enjoyable, it has to meet your needs, but it also has to inspire you. An Allez is a pretty inspiring bike to those new to all-out road bikes. I love mine for a bunch of reasons, but also because it looks as cool as steel and is a mini version of the mega pro bikes. These simple, silly inspirations motivate me to ride it as often as I can. Since this is a second bike for you, just go with your heart on it.
N.