Leben CS-300 compared to Red Wine

You might want to contact Vinnie Rossi at Red Wine and ask him, or maybe inquire about a loaner. I can't speak for Vinnie, but I've met him at a couple of head-fi shows in the NYC area, and he's a really nice guy.

John Devore was very helpful when I wrote to ask about amplifier options for my Devore 8's.

Thanks guys. I emailed Devore, haven't heard back yet. Vinnie was very nice, but hadn't heard the Leben. At one point he supposedly used the Nines himself to voice his gear (or so I read online), and his reviews are so phenomenal... makes me very curious. Of course, the RWA combo is more than twice the price of the Leben.

The Leben CS600 should also be consider with it's greater power (32w or 28w/ch) and flexibility to use different flavoured tubes to fine tune your preferred sound.

I own RW 30.2 and owned PrimaLuna Prologue Two before and to tell you the true, Prima is more powerful and offers you the endless tube rolling to your liking, however, as always, this is about the match and you should try it first, imo, cos like you wrote, to make such step and invest blindly isn't ideal, for any of them.
Me, bought RW blindly, ha-ha, but my main use of it is for AKG K1000 ear speakers, however my Canton CD100 sound simply wonderful through RW. I loved Primaluna to, but because of her limited volume attenuator it draw me away from her, but my Cantons were great through PL, think even better than RW, gave more dynamics and tighter bass. Have to mention, I upgraded to NOS GEC KT88 plus all my pre amp tubes were NOS Mullards as well and it changed the tonality dramatically, from an very good amp to amazing sounding one. The delicacy of RW makes people say about their capability to sound like SS/Tube amp, but this is very personal and from my impressions RW do not sound like tube one, its still SS amp, which have the delicacy that makes him sound bit like tube one, but than again, its not the same at all.
Going to keep RW for a while and see how the things will be developing after another 50 hours of burn in, its still a fresh sounding, but have to become more ripe/fully developed and when I am on his 100 hours I will start to listen more critically, but so far so good, great amp from Red Wine.
Just a little advice. You may want to check the used market or contact Vinnie about some trades he have and maybe you can score a nice set up for 50% of the new costs, but than with fully check&warranty and new batteries as well.

Good luck.