diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,20 @@
+3.0.1
+-----------
+* Fix performance issue of switch, dSwitch, accum, dAccum.
+
+3.0.0
+-----------
+* ArrowLoop instance now independent of base arrow's
+* Make PlanT newtype and add stop handling MonadPlus instance
+* API changes
+    * Added `filterJust`, `filterLeft`, `filterRight`
+    * Deleted Show and Eq instance of Event type
+    * Added Isos of ArrowUtil module
+    * Delete state monad handling.
+    * Delete unsafe primitives `cycleDelay`, `fitEx`, `unsafeSteady`, `loop'`
+    * Delete deperecated `passRecent`, `withRecent`
+    * Delete ProcessA ArrowReader instance and added `readerProc`
+
 
 2.1.0
 -----------
diff --git a/machinecell.cabal b/machinecell.cabal
--- a/machinecell.cabal
+++ b/machinecell.cabal
@@ -1,5 +1,5 @@
 name:                machinecell
-version:             3.0.0
+version:             3.0.1
 synopsis:            Arrow based stream transducers
 license:             BSD3
 license-file:        LICENSE
@@ -53,4 +53,4 @@
 source-repository this
   type:		git
   location:	https://github.com/as-capabl/machinecell.git
-  tag:		release-3.0.0
+  tag:		release-3.0.1
diff --git a/src/Control/Arrow/Machine/Types.hs b/src/Control/Arrow/Machine/Types.hs
--- a/src/Control/Arrow/Machine/Types.hs
+++ b/src/Control/Arrow/Machine/Types.hs
@@ -1,6 +1,7 @@
 {-# LANGUAGE Trustworthy #-} -- Safe if eliminate GeneralizedNewtypeInstance
 {-# LANGUAGE Arrows #-}
 {-# LANGUAGE RankNTypes #-}
+{-# LANGUAGE BangPatterns #-}
 {-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE UndecidableInstances #-}
 {-# LANGUAGE MultiParamTypeClasses #-}
@@ -180,7 +181,7 @@
         a b (f c, ProcessA a b c)) ->
     (b -> c) ->
     ProcessA a b c
-makePA h sus = ProcessA {
+makePA h !sus = ProcessA {
     feed = h >>> first (arr runIdentity),
     sweep = h,
     suspend = sus
@@ -707,26 +708,22 @@
 --
 -- Switches
 --
-switchCore ::
-    (Arrow cat, Arrow a2, Arrow cat1, Occasional t3) =>
-    (t4
-     -> a2 (t5, (t6, c1)) c1
-     -> (t -> t1 -> cat a (t2, t3))
-     -> cat1 a1 (c, b))
-     -> t4 -> (t1 -> cat a t2) -> cat1 a1 c
-
-switchCore sw cur cont = sw cur (arr test) cont' >>> arr fst
-  where
-    test (_, (_, evt)) = evt
-    cont' _ t = cont t >>> arr (\y -> (y, noEvent))
-
 switch :: 
     ArrowApply a => 
     ProcessA a b (c, Event t) -> 
     (t -> ProcessA a b c) ->
     ProcessA a b c
-
-switch = switchCore kSwitch
+switch sf k = makePA
+    (proc x ->
+      do
+        (hy, sf') <- step sf -< x
+        let hevt = fmap snd hy
+        (case (helperToMaybe hevt)
+          of
+            Just (Event t) -> step (k t)
+            _ -> arr $ const (fst <$> hy, switch sf' k))
+                -<< x)
+    (fst . suspend sf)
 
 
 dSwitch :: 
@@ -734,8 +731,18 @@
     ProcessA a b (c, Event t) -> 
     (t -> ProcessA a b c) ->
     ProcessA a b c
-
-dSwitch = switchCore dkSwitch
+dSwitch sf k = makePA
+    (proc x ->
+      do
+        (hyevt, sf') <- step sf -< x
+        let hevt = fmap snd hyevt
+            hy = fmap fst hyevt
+        (case (helperToMaybe hevt)
+          of
+            Just (Event t) -> arr $ const (hy, k t)
+            _ -> arr $ const (hy, dSwitch sf' k))
+                -<< x)
+    (fst . suspend sf)
 
 
 rSwitch ::