due to a fall I may need to replace my RD, currently have Apex and like it, is there a compelling reason other than ~12g to 'upgrade' from Apex to Rival? seems like they are comparably priced (within about $10+/- a few).

Tagged for interest.

Are you sure it's an RD problem and not a bent hanger or pinched cable?

But otherwise, you would be hard pressed to notice a performance difference between them as long as they are the same cage length and properly set up.

I thought the Apex is meant for a larger cassette with better gearing for climbs.

If you go for Rival RD, make sure that it would work for your cassette.

Apex and Rival are both available in short-cage (28t max) or medium-cage versions.

Having used both, I say go with whichever is cheapest (or whichever matches the rest of your groupset, if you are OCD about those sorts of things).

second time I've whammied this thing in about a month, first time was from a broken chain and bent the cage, this time on the fall I ended up with a slight ding on the body (possible I bent the hanger) but also got the cage again and it appears bent as well. the fall was near stationary, long story, cop car ran thru an intersection lights on no siren during rush hour and I hammered the brakes while I was still getting clipped in to avoid rear ending my riding partner and went down.

I have a 12-27 so a short cage is fine for me and the apex RD i have now is a short cage anyway.

If you have a habit of messing up your RD, I believe it would be more economical if you go Apex.

ya, not a habit, first RD i've ever wanged in my life, just happened to have done it twice in a month. lol