Being completely bias on the subject, I would say the Trapper is a great little carbine. I've had mine for about 4 years and bought it to keep my Blackhawk company.
I'm still working on a load for both the Blackhawk and the Trapper. I'm presently using Unique powder, a 250 gr. Hornady XTP/JHP, Fed. 150 primers in Win. cases. The last load was 8.5 gr. of Unique which appeared to be starting to push the pressure envelope in the Blackhawk. It was pushing that 250 grainer at an average 1233fps out of the Blackhawk's 4 5/8" barrel but a couple of the primers backed out a little and the case heads showed some flattening. I think I'll back off to 8.0 gr. and see what happens. According to Lyman's 47th, the max. load of Unique should be 9.3 gr. but I'm now a little leary of going more than maybe 8.3. For my peace of mind, do not use this load info without working up to it.
BTW, you might want to take that 1233fps with a grain of salt. It is an average of 12 shots over a Shooting Chrony Beta but that 8.5gr should not produce that velocity. It should be somewhere around 800fps.
Were I you, I would stick with one load for both the Trapper and 25-5 so as to not have one load too stout for one or the other. Mix-ups are bound to happen to the best of us.
Can't comment on the Ashley, don't have one.