Other than starting with a skilter, buying a ASM mini-G is something I am bummed that I did as a noob. (Although, admittedly, I had a very knowledgeable and helpful LFS compared to many, sadly gone now) While it did a good job for about a year as a noob tank for-now solution; it has burned out. I did even replace the pump and now that has crapped out too.
My tank never looked better than when the skimmer was working properly.
Now I am stuck because I won't repair this mini-G again. Ever since I got the new pump (feb 09?) the skimmer has not done well. I got maybe 5-10 cups of skimmate out since then. (10 would be a stretch) I definitely messed with the riser a lot trying to get it to produce. At best I got wet skim tea.
Since it was running so minimally, I figure I have essentially run skimmerless for like 6 months. I did add a HoB fuge as (ironically) I was having nitrate issues. The fuge seems to really have helped that.
Many times I have come to the conclusion that buying a high quality oversized skimmer that will last is an excellent decision. While reactors and auto top offs can overdose a tank, skimmers are not something that can really cause harm to a tank!
I have read Mojo~'s skimmer reviews and have a good idea what I am interested in, but will need to save a bit for it (thinking vertex 180)
My tank looks a bit struggling, but I did move the whole thing mid September.
Like many have said, there are ways to make it work without, but with so many examples of the ease and success and help they can provide (I think particularly to the ToTM comment) why would you steer newbs away? It's just not a bad or dangerous idea, IMO, and I am excited to finally get something decent on my system- to see what it pulls out, and how happy my reef is afterwards.
(sorry for reflection on this one)