The best replacement for msr is katadyn.

The best alternatives to msr are rated as following:
★★★★★  katadyn
★★★★  120 sr
★★★  l118a
★★★  mcx2
★★★  jetboil
★★★  tubbs
★★  msr x
★★  msrx
★★  atlas
★★  v911
★★  mcx
★★  nano cpx
★  cb100
★  l118
★  msr
★  h2cmr
★  intervention
★  mrad
★  as50
★  atlas snowshoes
★  novus fp
  primus stoves
  sr
  katadyn water filter
  cx2
  walkera
  v100d01
  vector ghost recon
  coleman
  tubbs snowshoes
  solo pro
  120sr
  atlas snowshoe
  katadyn filter
  primus

Your alternative for msr is not listed? Suggest!
Speaking about msr, one probably shouldn't forget about dx6i.

Other search terms related to msr and their ratings are:
★★★★★ dx6i
★ tbe
dx7
You have in mind a companion for msr and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of msr in all years. Click on graph for more.
msr
katadyn
120 sr