I really enjoyed last year's series with Eccleston. There were a couple of howlers but eps like The Unquiet Dead written by Mark Gatiss was fantastic and probably the best Who episode I've seen. The Tennant era started incredibly badly and while it's picked up a tiny bit, still isn't up to scratch.
I suppose what I dislike about the new Who is (aside from being overexposed) is it's just aimed too much at kids. It's too clean cut and they should make the Doctor more of an unpredictable character with elements of darkness. So far the only scenes where he's "intimidating" is when he's camply shouting down characters he wants to be quiet. The stories have fcuk all complexity too, it's just "encounter bad guys/beat bad guys/skip arm in arm back into the Tardis". Alot of the scripts are chair-squirmingly bad as well but again, probably for the kids' benefit?
Tennant's portrayal of the Doctor is really irritating to me, he never ever closes his mouth for more than 3 seconds and I just find his performance very grating to endure for the best part of an hour.