Tele zoom - DA 60 - 250 or DA 50 - 135 (+/- 1.7x TC)

Hi All,
I've obviously too much time on my hands, with the rain falling, work shut due to Central European flooding and the baby asleep. After watching a video about Jay Maisel I suddenly realised the only thing I needed to shoot like him was a good tele - zoom (ahem...OK, I'd also need a lot more talent and cool, but this is not what the post is about).
I'm still in the process of trying to work out which long-end focal length I'd like. This is a work in progress using an ongoing selection of Frankenlens combos from my 6x7 lenses, TC, etc. I have a 135/2.8 which is pretty nice, but whacking on the TC is a big jump and seems to attract flare like ants to honied eyes in a horror movie.
My question then, is this: has anyone used the 50 - 135/2.8 with a 1.7x TC and compared it with the 60 - 250/4? Some pics would be great.
I can think of some obvious pluses and minus:
Plus
When desired, bigger apeture (.i.e. when TC is off)
Minus
Losing water sealing
Slower AF
Slightly smaller apeture (F4.5)
I must have the wife from photo-heaven with dektol in her veins or something, as she just said: "Get the one you want the first time so you don't have to by it twice".)
Usage - general. The boy is 2 so autofocus needs to be pretty quick.
Any thoughts appreciated.

Cheers Dick - he wouldn't be my / our only subject (but probably the most important one). I can get him in focus with a medium format lens (without heavy sedation, I might add).

Ditto 18-135 and 60-250 is a great combo and covers most things. When closed down a bit the 18-135 is very good from 20 to 60 and at 60 it is on par with the 60--250 above that the * shines.