In reply to Bulls Crack:
That would be why you're recommending it. The slabs are beginner group paradise, and the quarry is an acquired taste (it's superficially loose but bolted).
To the OP: I've lived in Aberystywyth for most of the past 8 years, and "whizz up"* to North Snowdonia - Tremadog, The Pass, Ogwen, Gogarth, The Orme, Ysgo et al. far more often than I stop on route to climb something else. Same summer or winter. As others have said, decent bouldering at Tan-y-grisiau and Traws if you want to keep more local.
Anyone who tells you that the Rhinogyau is grit is lying, it's a coarse sandstone and whilst not unlike Peak/Yorkshire Grit is definitely not the same. Bits of nice cragging though.
If you want a partner for sport/trad/bouldering, drop me an email. Generally can't be bothered with trad over the winter though as it's too cold. Logbook on here is mostly up to date.
*proportional to Mansell Davies lorries, caravans, and general slow bastards