Does anyone have these?  I have a pair of Costa's that I love, but I want to get another pair that have interchangable lenses.  What I am mostly concerned with is, do the lenses become loose after changing them several times.  I had Oakleys and the lenses always seems to get loose after changing them several times.

Here is a link to them on Costa's website.

http://www.costadelmar.com/store/ProductInfo.aspx?productid=TS

Noever tried Costa Del Mars, I swear by maui jims.

I'm interested in hearing opinions on these as well, as I was <THIS> close to buying a pair yesterday.

Not the same style but for what it's worth.  I bought the Fluid ILS's to be able to change from the grey, to amber, to copper for bass fishing.  I love the glasses but they did loosen after a while and I ended up loosing one of the grey lenses.  Rather than paying $40 for a new lense I bough a pair of grey wave killers.  

I'm interested in hearing opinions on these as well, as I was <THIS> close to buying a pair yesterday.

Yeah, me too, that is why I was hoping for some input.  I can't help but think that if they are as good as the Costa's I have now, you can't beat $140 for basically 3 pairs of quality glasses.