I own or have owned 2 of the 3, and honestly think any of the 3 would be a good choice. Which seat would be best for you depends mostly on your RF goals, but I am thinking the Contender may be the best fit. But here would be my pros and cons as I see them on the seats:
ProComfort (I am assuming Evenflo Triumph because it fits the budget and Symphony doesn't)
Pros:
-Extremely comfortable seat for long trips
-Harness is always at the right hight
-Adjuster mechanism
-Easily my son's favorite seat for comfort and DH's favorite seat for ease of use
-FF Recline helps with head slump
Cons:
-One level line, so for really angled seats you may need a towel/noodle
-Bungee cup holders don't hold sippy cups well (minor complaint)
-RF height and weight not as high as some other seats
-In some cars, RF install can push the adjuster knob into the seats so it is hard to turn (I never encountered this issue in our Windstar)
Overall:
This is by far my favorite convertible seat that we have owned. If it fits into my Kia, we may be purchasing another once our youngest outgrows his infant seat. That being said, I am not a strict follower of the Extended RF rules. For our family, turning our kiddo forward earlier was a better fit, so the lower RF numbers aren't an issue.
MyRide65:
Pros:
-Great recline for both FF and RF (Kiddo was super comfy when sleeping on long drives when he was younger)
-Awesome cupholders (again a minor thing)
-Easy to use harness/buckle
-Very inexpensive right now (Have seen it for as low as $80)
Cons:
-HUGE! No kidding, this seat is really large and there isn't a way to adjust how much front to back space it takes up
-Very high up (I list as a con cause it was on your list, could be a pro for kiddo to see out the window and puzzling with other seats)
-Re-Thread harness
-No real upright angle (when kiddo is older and wants to be more upright there isn't an option for that
-Outgrown FF earlier than some seats
Overall:
This was a fantastic seat for when we had it (3 years ago) as our son grew out of his infant seat to sleeping toddler stage. I only recommend the other seats over this one because there are newer features.
Contender: (Have to preface this with the fact that this is the one I don't own. This is just from reading features and hearing others experience)
Pros:
-No re-thread harness (move the headrest and the harness moves to the right height)
-Adjustable headrest can be shorter when RF a little one to give you more space
-Higher weight and height regulations for extended RF
-Will likely get your kiddo to Booster stage
Cons:
-Adjuster foot only gives you one recline position both FF and RF
Overall:
A lot of people recommend these seats, and with the added features over the MyRide, I think this is a better fit if you are looking for extended RF over the Triumph ProComfort. If you keep an eye out for sales, you may even be able to do the Graco Size4Me, which is basically the Contender with multiple recline adjustments for a little added comfort and ease of install (Normally about $150ish)
That was a lot of info, but hopefully it's a little helpful for you! As with any seat, I would recommend going somewhere like Babies R Us to check the fit of the seat in the vehicle before purchasing. Or test it out before removing the tags, etc. so you can return it.
