I trained for Brighton marathon with Shotbloks because that's what they gave you on the day. I liked them, and opened the packets before I left the house. Whole, chewed, I don't think it matters - I never chewed them much
Mind you, I haven't trained with them since - got so fed up with them, and on the day I couldn't swallow them after 20 miles. They were good, though ...
Bits flying out of your mouth was quite entertaining, really ... anything to break the monotony ... 