I've been using running spikes for a couple of seasons now and I think they are great. I've always found that no matter which cricket shoes I wear I still find them bulky and cumbersome. Even if I wear my asics gel advance which are pretty light by comparison to other cricket shoes they still feel heavy to me.
BUT and that's a big BUT, they offer no protection if you get hit, you will be screaming blue murder. luckily I've only been hit once in nets and thank god nothing was broken. Its not a problem when fielding unless your one of those who fields with his feet, you just got to be careful when batting.