Newbie or not Newbie?

I've been a Cubase user for approx 800 years (or so it seems) since the Atari days.
I'm now deciding wether to upgrade to Cubase 4 or change platforms entirely. I can get Cubase 4 for about the same price as I would pay for Sonar 6 Producer, by using the Steinberg update path. I find Cubase easy enough to use, and powerful enough for my needs, but I'm sick of hardware dongles. My dongle has just died (possibly taking my laptop with it, although it could be the other way round) and I forsee it will be a b****y pain to get a new one, move the software to another system etc considering that my Cubase installation is now on a computer which is completely dead.
Finally, I reach my question.
Has anyone here had experience of both Cubase and Sonar?
If so what do you think I will loose/gain by changing platforms? Also, do you have any experience of dealing with the Sonar/Cakewalk user support system, as I find Steinberg/Arbiter/Yamaha are pretty slow to respond to any requests not directly related to sales.
Sorry about the "BIG" question.
Thanks for any advice.

Hi deety,

welcome aboard. There are no clear-cut answers. As you probably know, most people here will naturally prefer Sonar. What you will gain with Sonar you will lose in getting used to a new program/platform. This month's Sound on Sound has an in-depth review of both sequencers. You may want to give it a read!

One thing to keep in mind if you really like your Groove Agent and other Steinberg VSTs. While they interface extremely well with Cubase, it can be a little trickier to get everything to work as wonderfully with Sonar. I read a review on the new Groove Agent 3 yesterday and the reviewer tried it on both hosts with some difficulty using Sonar. I prefer using Cakewalk, but as said already, most posters here will.