In general SE ports are similar to line card ports and can be better (less contention) or worse. A _big_ gotcha though is that if you have 2 SE's in one chassis the behaviour can be unexpected.
For example with 4500R, with 2 SE ?? and IOS ver ?? you can only use one of the potential two ports on each card. The other one doesn't work at all.
As always, check the docs for the specific functionality that you need.
This is often quite difficult since there are very rarely negatives in the docs. e.g. Card xxx (surprisingly:) does not support yyy.
You therefore have to trawl through the hardware specs and the relevant feature set documentation for your OS version. Alternatively there are tools to help.
If you are spending money get your vendor to supply to your requirements and don't specify part numbers yourself. Let them carry the can.
Keep screen shots of info returned by tools 'cos the tools and the docs, and even two docs sometimes disagree. Just in case. If the web site is updated you will have difficulty in claiming that the goods were not as described.
I now recall that some reasonably modern kit has a management ethernet on the SE? I forget which box. I think maybe that the lightstream
1010 had something like that too.