The best replacement for 4.5 is 5.25 xdm.

The best alternatives to 4.5 are rated as following:
★★★★★  5.25 xdm
★★★★  4.8 patrol
★★★★  4.5.1
★★★  3.8 xdm
★★★  4.0
★★  6.5 moa
★  3.8
★  4.6
  114.3
  xdm 5.25
  7 grinder
  4.4
  5.25
  5 inch barrel

Your alternative for 4.5 is not listed? Suggest!
Speaking about 4.5, one probably shouldn't forget about iis.

Other search terms related to 4.5 and their ratings are:
★★★★★ iis
★★★★ vs2010
★★ visual studio 2010
vs 2010
You have in mind a companion for 4.5 and it is not yet here? Propose!



Google Trends

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4.5
5.25 xdm
4.8 patrol