CIAO features users liked best

5 - All of them!

9 - saving parameters; scripting capabilities

12 - The DM tools philosophy, prism, *_process_events

13 - scripts to do common tasks (e.g. exposure correct and combine
     multiple chips/observations)

14 - Threads

15 - command line, verbosity parameters, on the most part excellent ahelp

19 - The datamodel is brilliant.  I cannot function without it.  Also,
     the parameter interface is good, as it allows easy scriptability of
     tools.

21 - dm filename/filtering syntax; ease of scripting the various tools.

23 - Acis_process_events allows a lot of user control.  The documentation
     for CIAO tasks is extremely good.  Dmcopy and dmlist I am likely to 
     use several times per day.

24 - i like being able to apply filters on the fly, e.g., 
     dmcopy "evt2.fits[energy=500:1500]" evt2_lo.fits

25 - 1) command line oriented - allows real power use when scripted.
     2) moderately powerful, if occasionally buggy, support for regions in many formats.

28 - tools are generally fairly flexible if one knows enough 

30 - the dm syntax, and object oriented nature of sherpa

32 - Online threads, programs which apply many often-repeated tasks (i.e. acisspec, psextract)

38 - Extraction tools, processing....

39 - ahelp

40 - sherpa

43 - event processing and filtering
     response tools

47 - The history info recorded in the file headers is very useful although difficult
     to read due to formatting. 

51 - dmcopy 
     sherpa
     tg_reprocess.new

54 - Unix prompt input tools that do things well that are too complex to
     re-invent like: dmimg2jpg; csmooth (haven't used it but looks good).
     Also from unix prompt routines which acess CALDB data like: mkgarf; mkgrmf.

58 - command line capabilities and scriptibility;
     I intend to move over to sherpa, but am "fine where I am".  

60 - Everyone could study how to use CIAO by reading the thread by 
     himself/herself.

62 - sherpa

63 - I like the dm tools, especially dmcopy, dmlist, dmextract... all
     the basics are there, and it's easy to look at and manipulate fits
     files.  I also like that CIAO interface a lot (command-line, that is),
     since it's clean, pretty easy to script, and generally
     well-documented.

64 - I like the no-nonsense dmlist commands.

69 - sherpa - I really like this, especially with the slang language embedded in it.

70 - dmcopy is very powerful.
     psextract script is very convenient.

72 - coherent syntax
     extensive documentation

75 - data model filtering

80 - I haven't used anything that's very unique, but the standard plotting things are nice...

81 - the helpdesk is outstanding - always a quick response

     it is well designed and reliable

82 - Threads, Helpdesk

89 - ds9

90 - I like very much that you are still running in your native shell.
     The uniformity of the interface makes the learning curve much less steep.

99 - threads and ahelp

103 - sherpa is a good extension of xspec

105 - The presence of on-line detailed threads for all needs.

106 - The virtual filename syntax, the physical coord system, sherpa

107 - excellent documentation
      writing commands from unix prompt

108 - general reliability; sherpa; analysis threads

111 - * nice data model
      * sherpa is great

121 - XSPEC

124 - Sherpa scriptability is a win, especially being able to set up and 
      refer to model components by name. 

      Embedded scripting languages are good, so slang looks very 
      intriguing.  However, until there's better documentation on the
      interfaces between slang and ciao, it doesn't do me a lot of good.

      I do a lot of batch mode analysis, and sherpa seems to support that
      reasonably well.  (Features of xspec that drive me mad are the
      problems running it in batch mode, and the problems in scripting
      it.  xspec has many operations requiring user feedback in the form
      of 'yes' or 'no', and it is very difficult to set it up so that
      the appropriate responses can be fed to it.)

125 - CHIPS, Sherpa for HETG spectroscopy