Do you merge vampires?

The options are limited in size, so here's the detail:

• Yes, occasionally, I have decks relying on merged vampires
• Yes, but not frequently (I have decks with a copy of the base or adv version, just in case)
• No, no merged vampire is worth being in a deck
• No, I'd like to but it's too slow / too complicated / not worth the effort / doesn't work well (crypt building, merged mecanism)

Please explain why / why not.

For my part, I find there are some nice vampire once merged, but it's a bit complicated to use them casually.

Star vampires are maybe an exception, because I'd probably include 5 copies of the base version anyway and just add 1 copy of the merged version (or 4+1). It makes the crypt somehow unbalanced but not more than for a star vampire.
Eg. Nergal + Nergal adv

The real trouble is for non-star vampires: it doesn't work well.
Let's take for instance some Carna deck with Valerius Major. You'd probably be forced to play 3 Valerius adv + 1 base, because the advanced version has the nice anti-obf special.
But then your crypt is a bit crippled, and you can't play Epiphany (works only with base version).

If you merge it manually, it takes an extra turn which is quite a penalty when you intend to bring out 2 more vampires.

If you use Wider View, you'll even probably need 1 extra turn to fetch the right version (if you're lucky), for a total of 2 turns.