Not in my experience. I wear it all year in the UK. If anything I must be a wuss as I keep the liner in in summer & just wear a T-shirt under the jacket, & a couple more layers when it gets colder.
Best bit of kit I've owned. Totally dry, warm as toast in winter and pretty cool in summer. No sweatyness or stickyness like others with goretex liners. The dogs bollox imho
The HG Master & Cruise are designed for all year use. They have removable thermal liners, real Goretex waterproof/breathable membranes and vents.
The vents are very efficient. I opened mine a few weeks ago when we had >20C temperatures and they worked well. I wish I had remembered to do up the vents before riding last weekend when it wasn't so warm!
I have the Cruise, a touring partner has the Master. We are both happy. For longer trips in hot weather I recommend investing in some proper wicking layers which will help to keep your skin dry and help the Goretex to dissipate moisture more efficiently. These products are excellent http://www.thermalshop.co.uk/merino_base_layers