If you want the capability to fit and remove your guards quickly and frequently, then Raceblades are the way to go. They can be fitted in less than 5 minutes.
I use them on my Tricross and as has been said, they are not as efficient as full guards but better than none at all!
One other point, that although already mentioned, I found is
very important is to protect your frame where the mounting blocks sit. I used mine for the first time and when I took them off they had badly scratched the paint to the point where I had to use T-Cut to get the scratches out. It is a gloss black frame so stood out like a sore thumb and I was not happy

:?:
My solution was to cut up an old inner tube and put some strips under the mounting blocks which seemd to work OK
Hope this helps.
Gary.