ESS indentation

# I've been unhappy with ESS indention for some time, and finally got
# around to trying to adjust it to my taste. It didn't go well, and so
# I'm turning to the collective wisdom of this list for help.
#
# I don't think what I want is so exotic; basically I like how Rstudio
# indents things, which mostly means lining up things up by reference to
# the calling function. Here are some examples (these examples also
# available at __________ in case your email client doesn't like to use
# a fixed-width font):

#Rstudio:
mean(rnorm(100,
           mean = runif(1,
                        1,
                        10)),
     na.rm=TRUE
)

# ESS
mean(rnorm(100,
           mean = runif(1,
               1,
               10)),
     na.rm=TRUE
     )

# The Rstudio version makes it easy to see which lines are arguments to
# which functions, and I'd like to set ESS to use a similar indentation
# style. I've fiddled with all the ess.*offset variables I can find, but
# I can't seem to find a satisfactory setting.
#
# The biggest annoyance is the indentation of continuation lines. There
# have been several posts about this including
# http://emacs.1067599.n5.nabble.com/indentation-of-ggplot-code-and-ess-13-09-02-td322315.html
# which suggests the following setting:

# (add-to-list 'ess-style-alist
#              '(my-style
#                (ess-indent-level . 4)
#                (ess-first-continued-statement-offset . 2)
#                (ess-continued-statement-offset . 0)
#                (ess-brace-offset . -4)
#                (ess-expression-offset . 4)
#                (ess-else-offset . 0)
#                (ess-close-brace-offset . 0)
#                (ess-brace-imaginary-offset . 0)
#                (ess-continued-brace-offset . 0)
#                (ess-arg-function-offset . 4)
#                (ess-arg-function-offset-new-line . '(4))
#                ))


#This does improve simple examples such as turning this:

1 +
    2 +
        3 +
            4

into

1 +
  2 +
  3 +
  4

# though I would really like

1 +
2 +
3 +
4

# But it still leave more complicated things like

mean(rnorm(100)) +
  2 +
  mean(rnorm(100,
             mean = runif(1, 1, 10)), na.rm=TRUE) +
               2 +
               2

# I really don't understand why it makes sense to indent the "2's"
# differently depending on whether they come before or after the second
# "mean(rnorm(...". Compare this to the Rstudio indentation:

mean(rnorm(100)) +
  2 +
  mean(rnorm(100,
             mean = runif(1, 1, 10)), na.rm=TRUE) +
  2 +
  2

# Right. So I hate to be that guy, but seriously, how can I make ESS
# indentation behave more like Rstudio?