I had shockworks in my R34 GT-T, definitely not bad at all comfort wise with their standard rates. I wouldn't call it comfortable however.
Have had a set of BC V1s in my previous car and ridden in countless cars with BC BRs, only purchase these if you have $1300 to spend. If you're spending $1300 on coilovers for a R34 GTR I think you need to reassess your priorities. I see countless 50k+ builds running BCs and cry a little.
I've driven a MX5 with X-R coilovers with their 'Tarmac' spring rates and was pleasantly surprised with comfort and performance. Going off this I can only guess that X-C would be significantly better.
TLDR
- Buy BC BR if budgeting ~1300, don't cry when they ride shit.
- Buy MCA X-C with suitable spring rates if you want decent comfort (or fork out for reds), just talk to MCA.