I have never had any problems with Rainbow flowers, Bunches or Sendabunch. At Christmas I use Thompson and Morgan who do amazing poinsettia's and hibiscus. For the spring I use Scilly flowers who send large bunches of narcissus which smell beautiful.
As you can tell, I still have a number of elderly relatives remaining in the UK, several in residential care for whom a plant is really the only option.
On the one occasion that Rainbow flowers had a delivery problem due to snow on the roads, they replaced the flowers with fresh ones the following week.
The other thing I've found with these companies is that they are much cheaper than interflora and even local florists.
Hope this helps you a bit