Well, my personal experience is limited, but I have a 1x18 cab that is great - older model, 400watt. I knew a guy in college that got one of their 180 watt 1x15 combos, and he was really happy with it (not a gigging bassist mind you). The real problem with carvin is its inexcessability. The stuff looks great, and people can tell you all they want, but you just can't try it out! very few places have any carvin gear, and it is almost always older stuff. The old "let your ear decide" is unfortunately not possible. If you could try it out, go for it! I have also used carvin mixers (great for the price, not top-notch, but really cheap), carvin PA speakers - little ones, and I was really impressed with the sound/price ratio. Also, their amps - these are really the best thing I have had experience with. Solid and reliable. Sorry I couldn't be more help - you need to find someone (or many someones) who have used this exact rig.
good luck!
p.s. I hear the red line series is not all it is cracked up to be, but that could just be hearsay