Aesthetically it's nothing special, but you can only do so much when working with such tight performance requirements.
Actually, I think it's pretty nice looking. I'm still haven't figured out how to SSTO in 1.2, so that makes your ship extra impressive.
Thanks. I didn't mean I thought it was ugly or anything. I just wanted it to have a bit more distinctive look, but it ended up kind of generic because of weight minimization.
I think I should do another launch and try to optimize my ascent a bit more. This one
should have enough fuel, but I'd prefer a bit of a safety margin and it still has too much oxidizer.
For SSTO spaceplanes you really just have to keep in mind how jet engines work now. Instead of giving you a flat thrust, their thrust varies heavily based on speed and altitude. Once you break the sound barrier (340 m/s) your drag will decrease and thrust will rapidly increase, but it can be hard to break it if you don't have the TWR. Toggling your rockets on just for a moment to push you over can be helpful but obviously doesn't work with RAPIERs. Jet engines will only get you to a certain point before they stop producing thrust, so intake spam doesn't work anymore. This will generally be around 1000 m/s at 20km for turbo/ramjets and 1400m/s at 25km for RAPIERs. You can try to go faster by using lots of jets and building up speed lower in the atmosphere, but you run the risk of burning up. And finally, since the jets can't get you as fast as they could previously, you need more rocket fuel to get into orbit.