You say that synching issues are easy to resolve. That's not my experience. I find this immensely frustrating and discouraging from what would otherwise be an excellent way of reading comics. Just about every time I've bought a comic on the Comixology website (most recent example: FF 13), it DOES NOT appear on my Kindle Fire. Now I have FF 12 and 14 on my Kindle, but cannot read the issue in between. (#13 did not appear as available for purchase on the Kindle, which is why I bought it on the website.) I'm very far from a neophyte with technology, but have been unable to figure out how to get the purchased issues to appear on my Kindle.
June 7 2012 update: I rarely use my Kindle now, preferring to read comics on my Galaxy Tab. I'm not having any problem seeing my purchases anymore. I have checked on the Kindle, and it's no longer a problem there. I'm extremely happy with my digital comics! The only problem I have is that I keep having problems buying comics in the Comixology app. However, I can buy them at their website in a browser then download them in the app.