Well, I grew up in Worthing but from the first time I came to Llandudno at the age of 7 to visit my father's family, I preferred Llandudno. I am therefore somewhat biased but I will try to be fair to Worthing.
"In my day" Worthing was one of the places to which people retired in large numbers, so it had quite an elderly population. The town has expanded since then and is a bit more lively. Worthing is much bigger than Llandudno and is composed of a number of parishes which grew together over the years but some of these retain a local identity and organise their own events each year. The towns along this part of the south coast have similarly spread out and merged together.
The public gardens are well maintained and Worthing has world class bowling greens. The prom is long, not as broad as Llandudno's and has less seating. Cycling is currently allowed on the prom and there are cycle routes along the proms or close to the sea from Worthing to Brighton and I've cycled these (most recently last year) without any problems. I've also walked along the prom without encountering any problems with cyclists - though there are always a few who go a bit fast. As Worthing is pretty flat it's good for cycling but the roads are much busier than up here.
The town centre shopping area near the seafront is pedestrianised and quite pleasant but there are also some shopping precincts which are virtually deserted, while many local shops closed down years ago when the big supermarkets started to open. There are a number of large hotels along the prom but despite Worthing's slogan of "Come to Sunny Worthing", I would imagine that most holidaymakers would be older people, as there's not much in the way of tourist attractions.
The pier and seafront shelters seem to be in good condition and provision of public toilets is neither better nor worse than Llandudno's.
The beach retains its traditional wooden groynes, which control the longshore drift but not the seaweed. The banks of shingle are natural and there's no problem with wind blown sand, as there isn't any - Worthing beach is largely mud! (I'm not being rude here, during an A level geology class we analysed the beach material and very little of it was sand.) My photos are rather misleading because in my experience the sea at Worthing is rarely blue; it may be grey, green or brown but blue is not its usual colour. The beach slopes very gently and when the tide goes out it goes a long way. To get to the sea, it is then necessary to negotiate the shingle and trek across a wide expanse of mud with hard-packed ripples and anyone who wants to swim rather than paddle still has quite a way to go. I'm not sure how well the seaweed is managed these days but there are banks of vigorous seaweed offshore and a good onshore gale redistributes large amounts onto the shingle, where it can gather in huge piles. When I lived in Worthing, the seaweed would then start to rot and attract flies and on a bad day we could smell it at home, 3 miles inland. Hopefully it is now removed more quickly (it's a tractor job). At least the sand at West Shore doesn't smell!
Worthing is not nearly as scenic as Llandudno but the rolling country of the South Downs behind Worthing is very pleasant.
I'd like to comment on the Christmas lights for Wrex's benefit. Unfortunately I can't, as Christmases in Worthing have been spent with family and I've had little reason to go to the town centre.
Even though Worthing is a large town the hospital seems to be periodically under threat of being downgraded and the hospitals along the south coast have different specialities, so depending upon one's aliment it may be necessary to travel some distance. This isn't entirely new and the area's maternity hospital has been a couple of towns away for a long time, with the result that, like many people from here, I was born in Shoreham-by-Sea.
Dave, I'm not sure if that answers your question. Worthing is pleasant but Llandudno is lovely and this is where I choose to live!
I'll find a few more photos of Worthing. Though I doubt I've bothered to take many when the sea's been its usual colour.