New EF 24-105mm f4L IS USM - worth the upgrade?

EF 24-105mm f4L IS USM v Canon EF 28-135 F/3.5-5.6 IS USM

Currently have the Canon EF 28-135 F/3.5-5.6 IS USM lens.
Is worth upgrading to the EF 24-105mm f4L IS USM ?
Anybody know the pros & cons?

24-105 is rated as a cracking lens

I have the 28-135 and am considering the same question. At f/8 the 28-135 is a pretty decent lens and wide open it is not terrible.

The advantages of the 28-135 are that it is lighter weight for a carry around lens and has a longer telephoto reach.

The advantages of the 24-105 are the constant f/4 aperture, better optical performance wide open and slightly wider at the wide end. Since it is f/4 and high quality optics you should be able to get good results and maintain auto focus if you add a 1.4x Tamron or Kenko teleconcoverter.

Right now it is not a priority for me to replace the 28-135 with the 24-105, but in the long term it may happen.

I used to own the 24-70 2.8L and now I have the 24-105 4L IS, to be honest to you, I cant really tell the difference between the two at all focal length. And if you do use DOF more than 2.8, the IS feature really rock!!

Pro: if you want a walk around lens and you use this focal length a lot, it makes up for the price. Newest generation IS and faster at the long end.
Cons: Cost

I've never used the 28-135, but I can tell you the 24-105 is a terrific lens, in all regards. Technically its sharp wide open at all focal lengths, AF is silent & fast and IS really does give you three stops better hand held. Practically, its a nice size & weight and feels well matched to the 20D. If you get one, make certain the date code is UT10xx or higher to ensure you get a copy that is not affected by an unusual lens flare problem that was noted in earlier copies (also indicated by a small blue dot on the box).
I highly recommend the 24-105 as an excellent every day lens.

The 28-135 is a very nice lens. The 24-105 is a GREAT lens. I shot about 10 minutes with the 24-105 and gave the 28-135 to my son.... We're both happy.

i did it 2 days ago

i wanted to replace the 28-135IS for a while, and was looking at the 24-70 f2.8L but after doing some research and also looking to my photographic needs i decided to buy the 24-105 f4L.
the f4 is no problem for me as i shoot outside most of the time.

Great travel and day to day lens that you can keep long term.

It must be a good lens, in the UK you can not get hold of them.

yes but that's also because of problems with ealier models having lens flare problems

here in holland they're finding the ways to the store slowly now.
the one i bought at my local shop was the first they got from the new batch.

Try Mifsuds - they had a delivery last week...

My statement was a bit of a tonque in cheek statement. I originally ordered a 5D kit, and cancelled it with the problems with the lens and just got a 5D. Now in the UK every where you look there is 5D kits, but the lens is still hard to get hold off. I have seen the lens fitted to a 5D in Jessops Lancaster, and the lens was a bit bigger than I thought, as I wanted this as a walk around lens finding the 24-70L a bit on the heavy side. I am waiting now till Jan/Feb before deciding if to get one, but the comments on how good it is are still pushing me towards it.

Some samples

www.pbase.com/vciinc/t​ests